Programming Libraries and Toolkits with PNG Support

Application toolkits allow developers to add image-handling capabilities to their own applications; this page lists the ones that offer PNG support, either for reading or writing or both. Plug-ins and datatypes that are more relevant to end users are still listed on the miscellaneous apps and browsers pages.

As with the other PNG-applications pages, links to home WWW sites or to downloadable versions are provided where known, but if a link is broken, check the location and see if an updated version is available (and please tell Greg!). Relevant operating systems are printed in (parenthesized italics).

These are listed alphabetically, more or less:

• 7-Zip [Igor Pavlov] (many) - all versions? freeware (LGPL) with C++ source. (This is primarily a compression-archiver utility, but it includes an independent implementation of the deflate algorithm used in PNG. [One would still have to add the zlib headers and Adler-32 checksum to the output stream before using it in PNG images, however.])

• ActiveListBar [Infragistics] (Win32) - all versions? read/write; commercial. (This is a navigation control with the look and feel of Outlook. PNG is supported for various icon sizes and presumably also for background images, etc.)

• ActiveTreeView [Infragistics] (Win32) - all versions? read-only; commercial. (This is an extension of the TreeView control that supports icons, background images, etc.)

• akPNG.datatype [Andreas Kleinert] (Amiga 68k/PPC/Amithlon) - all versions; read-only; transparency support (but no alpha support?); native PowerPC support available; uses libpng and zlib; freeware. (PPC versions prior to 45.x, formerly shareware, are now also freeware. Click here if links break.)

• Animation MNG ActiveX [JComSoft /Jin Hui] (Win32) - all versions; read-only; MNG support; shareware? (This is an ActiveX control for displaying PNG images and MNG animations. It appears to be a new product as of October 2002 and is available only by e-mail request.)

• Blitz3D [Blitz Research / Mark Sibly] (Win32/DirectX) - all versions? read-only; commercial. (This is an integrated development environment [IDE] incorporating a 3D game engine, design package, custom programming language [hybrid of BASIC and C], and compiler.)

• Blorb - see Glk below

• BMGLib [Scott Heiman] (Win32) - version 2000-04-07 and later; read/write; uses libpng and zlib; freeware with source. (This is a DLL that generally supports simple reading and writing of bitmaps, but with special emphasis on doing so in OpenGL programs.)

• Ca3D-Engine [Carsten Fuchs] (Win32, Linux/X) - all versions? read-only? freeware/commercial. (This is an OpenGL-based 3D game engine; PNG is supported as a texture format.)

• CamlImages [Jun Furuse and Pierre Weis] (Caml) - all versions; read/write; requires libpng and zlib; freeware (modified GPL) with source. (This is an image-processing library for Objective Caml [O'Caml].)

• Carnegie Mellon Graphics [Geoff Washburn, Mark Stehlik, Jevan Saks, Sabrina Haskell, Ed Latimer, et al.] (Win32, Mac OS, Mac OS X, Unix) - all versions? read-only? requires libpng and zlib; freeware (BSD) with source. (This is a "simple, cross-platform 2D API for C++." A Java version is being developed.)

• Ch PNG [Stephen Nestinger] (Win32, Unix/X, Mac OS X?) - all versions; read/write; freeware with C/Ch source (for PNG add-on only). (This is a "Ch interface to libpng." Ch is a proprietary, multiplatform C/C++ interpreter, and Ch PNG provides a wrapper for libpng that allows all of its functions to be called from a Ch program, too. Version 1.0 appears to support only Win32 and Linux, however.)

• CImage [Anthemion Software] (Win32) - all versions; read/write; freeware (BSD) with C++ source. (This is "an MFC class for manipulating images." It is based on code written by Alejandro Aguilar Sierra.)

• ClanLib [Magnus Norddahl, Daniel Vogel, et al.] (Linux, Win32, BeOS) - all versions; read-only; full alpha support? uses libpng, zlib, Hermes and optionally ImageMagick; freeware (LGPL) with source. (This is an SDK for developing games. PNG is an optional image format that can be used for any image-related task supported by the application, such as sprites or 3D texturing.)

• Closure [Gilbert Baumann] (Unix/X) - all versions; read-only; freeware (GPL) with source. (This is a web browser written entirely in Common Lisp [the Allegro variant is preferred], including a basic PNG decoder [src/renderer/png-images.lisp] and zlib/inflate implementation [src/net/deflate.lisp]. It appears to have died quietly in June 1999, however. Note that the home page does not link to the latest source code; see this directory for newer code. Also see CL-PNG below.)

• CL-PNG [Harald Musum] (many) - all versions; read/write; freeware (LGPL) with Common Lisp source. (This is another PNG and zlib implementation written in Common Lisp. It appears to have died in June 2001, however, about two weeks after it started.)

• cl-zlib [Alberto Riva] (Linux, Win32) - all versions; read/write; requires zlib; freeware (BSD) with Common Lisp source. (This is an Allegro Common Lisp wrapper for the regular zlib shared library or DLL. Like zlib, it provides no PNG support itself, but it can be used to implement a PNG encoder or decoder. See also the pure Lisp zlib implementation in CL-PNG, above.)

• CMacPNG [Noriyuki Horiuti] (Mac PPC) - all versions; read/write? requires libpng and zlib; freeware with C++ source. (This is a "class is for Macintosh to handle PNG files.")

• ComponentOne Chart [ComponentOne] (Win32) - version 6.0(?) and later; write-only; commercial. (This is a presentation-graphics toolkit with both interactive and programmable interfaces. It can do both 2D and 3D charts and supports MSVC, Visual Basic, Delphi, and Borland C++ Builder. It was previously known as Olectra Chart.)

• Crystal Space [Jorrit Tyberghein and the Crystal Space Team] (Unix/X, DOS, OS/2, Win32, BeOS, NeXTStep/OpenStep, Rhapsody, Mac OS, Amiga) - version 0.10 and later; read-only; MNG support (read-only) as of version 0.96(?); uses libpng, zlib and optionally libmng; freeware (LGPL) with source. (This is an open-source 3D game engine written in C++ that compiles on multiple platforms; it also includes a number of demo levels. PNG support was added by Andrew Zabolotny.)

• CscHTML [Steven "Count Zero" Kordik] (Unix/GTK+) - all versions; read-only; full alpha support; requires libpng and zlib; freeware (GPL) with source. (This is an HTML widget for GTK+, with both C and Perl bindings. It is used by the CSCMail browser/e-mail client.)

• CWebImageDC [Randy More] (Win32) - all versions; write-only; uses libpng, zlib and HIPNG [see below]; freeware. (This is an MFC wrapper class that "provides a memory-based device context into which an image may be drawn using standard [Win32] GDI calls. The resulting image may then be saved as either a PNG file or written to a CMemFile for insertion into a CHttpStream." Source and a demo project are included.)

• CxImage [Davide Pizzolato] (Win32) - all versions; read/write; uses libpng, zlib and FreeImage (see below); freeware with C++ source. (This is a C++ class to "load, save, display, and transform images in a very simple and fast way." It is Windows-specific due to "some particular constructors and the painting functions." Read/write MNG support is available as a separate CxImageMNG module.)

• DaVinci Graphic Library [Herd Software] (Windows 3.x, Win32) - all versions? read/write; full 16-bit support; no alpha support? shareware. (This is a set of DLLs and online documentation that supports conversion and manipulation of many bitmap and vector image formats. Alpha support appears to be limited to TIFF and BMP, at least as of version 3.0. German pages also available.)

• DBPix [ammara.com] (Win32) - all versions; read/write? shareware. (This is an ActiveX "image control for building database applications with picture-handling capabilities." It can store and retrieve compressed images in databases and recreated them on disk in various formats, including PNG, and it has Visual Basic, C++, and other language/application interfaces.)

• Delphi [Borland] (Win32) - version 6 and later; read/write; commercial/freeware. (Delphi's native PNG support is available via CLX only; the older VCL component library doesn't support it.)

• DirectFB [Denis Oliver Kropp, Andreas Hundt, and others] (Linux/fb) - all versions; read-only; freeware (LGPL) with source. (This is a "thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, integrated windowing system with support for translucent windows and multiple display layers on top of the Linux framebuffer device." It includes bitmap and video loaders, including PNG.)

• DirectX [Microsoft] (Win32) - version 8 and later; read-only? uses libpng and zlib; commercial. (This is Microsoft's API to expose hardware-specific features to software, especially 3D acceleration to games. According to newsgroup postings by Tony Cox [e.g., on 21 May 2001 and 24 Sep 2001], "the D3DX utility library in DX 8.0 has a comprehensive bitmap file loader that understands lots of file formats, including PNG." Search Google for further info.)

• DISLIN [Helmut Michels] (DOS, Unix, VMS, Win32) - version 7.2 and later; write-only; freeware or commercial, depending on platform and compiler. (This is a high-level plotting library for data visualization. It can do both 2D and 3D plots and supports C, Fortran77, Fortran90, Java, Perl and Python.)

• Doc-to-Net [Skyline Tools] (Win32) - all versions? write-only; commercial. (This is a real-time conversion tool designed to be used as a CGI application; it allows scanned documents and "unsupported" image formats to be converted to PNG, GIF or JPEG on the fly and served to the user. It also supports some basic image-manipulation capabilities such as edge-detection and anti-aliasing.)

• EZTwain Pro [Dosadi / Spike McLarty] (Win32) - version 3.0 and later; read/write; uses libpng and zlib; commercial. (This is a DLL convenience wrapper for the TWAIN image-acquisition API, callable from most languages [including C/C++, Visual Basic, Visual FoxPro, Delphi, LabView, etc.]. It can read, write and scan to PNG.)

• FabPAINT [Fabrice Foray] (Win32) - all versions; write-only; uses libpng and zlib; freeware; 197k. (This is a drop-in replacement for the CAPAINT DLL, which appears to be part of the commercial CA-Visual Objects product [and which itself may have been based on an old version of Ulrich von Zadow's PaintLib, below]. In addition to PNG, it includes support for TIFF and JPEG.)

• FreeImage [Floris van den Berg / Hervé Drolon] (Win32, Linux/Qt, Mac OS X) - all versions; read/write; alpha support; MNG and JNG support (read-only) as of version 2.1.0; ICC profile support as of version 3.2.0; 16-bps support as of version 3.7.0; uses libmng, libpng and zlib; freeware (GPL or FIPL) with C++ source. (This is a library/DLL with support for reading and writing multiple image formats, including PNG; it also has a growing number of image-manipulation capabilities. Ease of use has been a design goal.)

• FXPy [Lyle Johnson] (Win32, Unix, etc.) - version 0.99.118 and later; read/write? requires libpng and zlib; freeware (LGPL) with source. (This is a "Python extension module that provides an interface to the FOX GUI library.")

• gd [Thomas Boutell] (many) - version 1.6 and later (or version 1.2 or 1.3 with Greg's gd1.2-png-addon or gd1.3-png-addon); read/write; palette support only in versions prior to 2.0; nearly full alpha support in version 2.0 and later (7 bits rather than 8; only binary transparency in earlier versions); requires libpng and zlib; freeware (BSDish) with source. (This is a popular drawing library written in C. Traditionally it was GIF-only, with PNG support planned for version 2.0, but Unisys legal action in 1999 prompted the author [who was also leader of the original PNG development effort] to add PNG to the 1.x series, replacing the old GIF support. Version 1.6 had broken transparency and RGB support, no grayscale support, and in some cases wrote larger palettes than it needed to, but those problems were fixed in 1.6.1 and later releases. Support for JPEG and Windows BMP formats was added in version 1.8.)

• GDFP [Mike Bradbery] (many) - all versions; write-only; requires gd, libpng and zlib; freeware (EFFL) with source. (This is a FreePascal interface to the gd library above.)

• GDI+ [Microsoft] (Win32, Win64) - all versions; read/write; commercial (incorporated into Windows XP and later, and available as a downloadable add-on for apps targeted at Windows 98 and later). (This is the device-independent graphics API built into newer versions of Microsoft Windows.)

• gdk-pixbuf [Federico Mena-Quintero and others] (Unix/GTK) - all versions; read-only? full alpha support? requires libpng and zlib; freeware (LGPL) with source. (This is a GDK library that can load various image formats and render them into various drawables and buffers with optional scaling and compositing. Reportedly it will be integrated into GTK+ 1.4.)

• GD.pm [Lincoln D. Stein] (Perl) - version 1.20 and later; write-only; requires gd, libpng and zlib; freeware (Artistic) with source. (This is a Perl wrapper for the gd library above. Despite the claim on the home page, newer versions may be available at CPAN.)

• Glk [Andrew Plotkin, David Kinder, and others] (Unix/X, Win32, etc.) - all versions? read-only; freeware. (This is an "interface standard for interactive fiction," a la Adventure and Zork; there are a number of platform-specific libraries that implement it, including XGlk and Windows Glk. Technically, PNG support is required only by the Blorb resource-file layer, but "the Glk portable I/O library uses Blorb as a resource format." See also the Glk archive and Glulxe on the miscellaneous apps page.)

• glpng [Ben Wyatt] (Win32, etc.) - all versions; read-only; requires libpng and zlib; freeware (zlib license) with source. (This is a utility library to load PNG images and bind them to OpenGL textures. Reportedly it is also a good general-purpose example of how to use textures in OpenGL. As of early 2000, it still includes the source code for libpng 1.0.2 and zlib 1.1.3, plus a static Win32 library [glpng.lib].)

• GraphApp [Lachlan "Loki" Patrick] (Unix/X, Win32) - version 3 and later; read/write? uses libpng and zlib; freeware (BSDish) with source. (This is a cross-platform GUI toolkit with particular emphasis on internationalization and Unicode support. It includes GNU's Unifont, stored in PNG format.)

• GraphicEx [Mike Lischke] (Win32) - version 8.0 and later; read-only; includes a Pascal port of zlib; freeware for non-commercial use, with source. (This is a Delphi [Pascal] extension to load various image formats, including PNG.)

• GraphiX/FP [Michael Knapp] (DOS, Win32, Linux/SVGA) - version 3.0 and later; read-only (write support planned); freeware (LGPL) with Pascal/assembler source. (This is a direct-hardware-access SVGA graphics library for FreePascal, with mouse support, font support, image-handling and image-manipulation capabilities. There is also an older version of GraphiX for Borland Pascal 7, but it does not support PNG.)

• GtkHTML [Anders Carlsson, Ettore Perazzoli, Jonas Borgström, Radek Doulik, Larry Ewing, Miguel de Icaza, and others] (Unix/GTK) - all versions; read-only; requires gdk-pixbuf, libpng and zlib; freeware (LGPL) with source. (This is a "lightweight HTML rendering/printing/editing engine." It was originally based on the KHTML widget by Torben Weis, Josip A. Gracin, and Martin Jones.)

• HIPNG [Alan Algustyniak] (Win32) - all versions; write-only; freeware. (This is a Windows-specific static library that simplifies writing a PNG image to a single call. It has two interfaces, one for converting Windows DIBs to PNGs and another for writing raw data to a PNG file. C++ source code and a static Win32 library are included. See PNG Source Code and Libraries for libpng and zlib, which are also required.)

• HTMLayout [Terra Informatica] (Win32) - all versions; read-only; full alpha support; uses libpng and zlib; commercial. (This is a lightweight HTML/CSS rendering component [DLL] with no dependencies on other browsers or browser components. PNG is supported for both foreground and background images, including with alpha-transparency. A demo browser app is freely available for download.)

• Ilib [Craig Knudsen] (many) - version 1.1.2 and later; read/write; truecolor support only; no transparency support; requires libpng and zlib; freeware (GPL) with source. (This is another drawing library, similar to gd [above] in basic functionality, but with broader image-format support, different font support [X11 BDF fonts instead of TrueType], and different sample apps [including a contact-sheet generator for indexing images]. It also comes with a Perl interface.)

• ImageEn [Hyrix Technologies] (Win32) - version 1.2(?) and later; read/write; shareware. (This is a "component suite for image processing, viewing and analysis" that works with Borland Delphi 3 and 4 and C++ Builder 3 and 4. A corresponding component suite for Visual Basic, ImageEn OCX, is also available.)

• ImageFileLib [Michael Vinther] (Win32) - all versions(?); read/write; MNG support; freeware with Pascal source. (This is a Delphi library to read and write several image formats, including PNG and MNG. It does not appear to support the more complex MNG features such as JNG and delta-encoding.)

• Image Format Library - see ImageVision Library below

• ImageGear [AccuSoft] (Unix, OS/2, Macintosh, Windows 3.x, Win32) - version 6.0 and later; read/write; full alpha support? (This is a programming library supporting numerous image formats, both display and conversion; it includes Visual Basic and ActiveX controls/DLLs/whatever, Java support--both classes and Beans--and claims to be fast.)

• ImageLib [Skyline Tools] (Windows 3.x, Win32) - all versions? read-only? commercial. (This is a Windows-specific DLL with Delphi support; it claims "support for most PNG formats.")

• Image Library [Colosseum Builders / John Miano] (many) - version of 1 May 1998 and later; read/write; alpha support; older versions write invalid zlib streams (and therefore invalid PNGs--fixed as of version 4.2); freeware with C++ source and, as of version 4.0, Delphi Pascal source, as well. (This is a library of C++ and Pascal sources for various image formats, including PNG. It includes Win32 executables and MSVC and Borland makefiles. The zlib/deflate bug was evidenced by "distance too far" errors in decoders based on zlib 1.2.1 and later, which do stricter bounds-checking than older versions did. Note that, as of June 2006, the latest version of the library [4.3] is actually on the author's source code page, not the main page listed above.)

• ImageMagick [John Cristy] (Unix, VMS, Win32, Macintosh) - version 3.6.3 and later; read/write; full gamma support; full chromaticity support? broken support for sub-8-bit grayscale PNGs in versions prior to 5.1.0; minimal MNG support as of version 3.9.2 and full MNG-LC support (read/write) as of version 4.2.4 (broken in versions 5.2.7 through 5.3.6); JNG support as of version 5.5.2; requires libpng and zlib; freeware with source. (See also Bob Friesenhahn's C++ interface to ImageMagick, Magick++.)

• ImageMan ActiveX Suite [Data Technologies] (Windows 3.x, Win32) - all versions? read/write. (This is a set of Visual Basic and ActiveX controls/DLLs/whatever, for image manipulation and conversion.)

• ImagePDF [Apex Internet Software] (Unix, Win32) - all versions; read-only; "retains most relevant image tags," possibly including text annotations; commercial. (This is a command-line program and shared library/DLL that converts images to Adobe's PDF format.)

• Image-Pngslimmer [Adrian McMenamin] (Perl) - all versions; read/write; freeware (Artistic) with source. (This is a Perl module to improve PNG compression on the fly, either by removing ancillary chunks or by recompressing and optionally refiltering the pixel data. Tarballs are available from CPAN.)

• Imager [Arnar Mar Hrafnkelsson] (Perl) - version 0.05 and later; read/write; full alpha support as of version 0.31; requires libpng and zlib; freeware (Artistic) with source. (This is a multi-image-format Perl module written in C. Imager's feature set is similar to that of gd and its Perl interfaces; it provides read/write support for several formats and supports image-blending, gradients, fonts, and so forth.)

• Imagery [Ursus Computing] (Windows 3.x, Win32) - version 1.0 and later; read/write? (This was an image-manipulation library with file support for PNG, JPEG, TIFF, etc.; various modification tools [blur, edge-detect, contrast, resample, etc.]; and some demo apps, including a viewer. It is now part of PiXCL Tools, below.)

• ImageScript [Jan Verhoeven] (Windows 9x/ME) - version 2 and later; read/write? freeware. (This is a "tool to convert, resize, copy and move" various image formats, including PNG, "under control of a script that you can create from, e.g., Delphi, VB, MS Access 97, etc.")

• ImageVision Library [Silicon Graphics] (IRIX) - version 3.0 and later; read/write? uses libpng and zlib. (This is a multi-format image manipulation library, also known as "IL." It uses SGI's Image Format Library to actually read and write image files; IFL is also available for Windows 9x/NT. IL 3.1.1 apparently corresponds to IFL 1.1.1, etc.)

• ImageX [Fath Software] (Win32) - version 2.0 and later; read/write; commercial. (This is an ActiveX control [OCX] for import, export, and conversion of various image formats. It can be used with Visual Basic, Visual C++, Access, Delphi, etc.)

• Img [Jan Nijtmans] (Unix/X, Win32) - version 1.0 and later; read/write; uses libpng and zlib; freeware with source. (This is a multi-format image-processing extension for Tcl / Tk. Versions of Tk prior to 8.3 required a patch in order to support the writing of alpha/transparency info; as of version 8.3, the patch is integrated into the core package.)

• ImgDLL [Smaller Animals Software] (Win32) - version 3.7(?) and later; read/write; full alpha and gamma support claimed; uses libpng and zlib; commercial. (This is a multi-format, file-based image-processing DLL/LIB for use with VC++, Visual Basic, etc. It has been mostly superseded by ImgSource, below.)

• ImgSource [Smaller Animals Software] (Win32) - all versions; read/write; full alpha and gamma support claimed; uses libpng and zlib; commercial. (This is a multi-format image-processing DLL/LIB for use with VC++, Visual Basic, etc. Unlike the older ImgDLL [above], ImgSource can read images from and write them to arbitrary sources, and it has more processing functions.)

• ImgX [Designer Controls] (Win32) - all versions? read/write; commercial; requires separate purchase of ImgSource, above. (This is an ActiveX DLL for Visual Basic that supports various forms of image manipulation.)

• Imlib [Red Hat Advanced Development Labs, Enlightenment team] (Unix/X, Unix/GTK) - all versions? read-only; partial alpha support (only binary transparency); requires libpng and zlib; freeware (GPL) with source. (This is a "general image-loading and rendering library" that transparently handles many formats without the need for the programmer to know any details of the formats or of the interfaces to their programming libraries; claimed to be fast.)

• Io [Steve Dekorte] (Unix/X, Win32, Mac OS X) - version 2002-11-24 and later; read-only? uses libpng and zlib; freeware (BSD) with source. (This is a "small prototype-based programming language" [and desktop environment] inspired by SmallTalk and other object-oriented languages.)

• janGraphics.dll [Jan Verhoeven] (Windows 9x/ME) - all versions? read/write; freeware. (This is a "multi-threaded COM-object to convert between the [bmp,gif,png,jpg] image file formats, including (optional) resizing, GIF transparency and JPEG compression quality adjustment." It can be used with Visual Basic, Delphi, MS Office apps, etc.)

• Java Advanced Imaging API [Javasoft/Sun] (Java) - version EA2 and later; requires Java 2 SDK (a.k.a. JDK 1.2 or later); read/write; full alpha support; full gamma support; read/write sRGB support (all gamma and chromaticity properties made available to app, but actual pixel-modification is limited to gamma); no iCCP support. (This is native PNG support in a standard Java extension; it does not use native code other than zlib [which is built into Java since JDK 1.1]. See also the documentation on the PNGEncodeParam and PNGDecodeParam classes, which provide a nice overview of the scope of the API. The API is available in two parts, one for image I/O [including PNG] and one for the rest of JAI's image-processing classes. The first can be used independently of the second. Note also that this is distinct from the native ImageProducer PNG support coming to the Java 2 / JDK 1.3 core [see the 4 May 1999 entry on the PNG News page] and that a new image-I/O API is being developed that will be independent of JAI. Some information about the latter is available here, though it is no longer completely accurate.)

• Java Image Content Handlers [ADI Limited / Justin Couch] (Java) - all versions; read-only; uses libpng and zlib; freeware (LGPL) with C++ source. (This is reportedly a fast and efficient image library--it uses native libraries for decoding--with support for PNG, JPEG, TIFF, GIF, BMP, TGA and PBM/PGM/PPM. As supplied, it is designed for Java 2 [JDK 1.2], but source code is included, and it can be trivially modified to work with JDK 1.1. Write support will probably appear in a separate package. As of October 2001, code newer than the stable 1.0 release is available only via CVS, as noted on this page.)

• Java PNG [VisualTek] (Java) - all versions; read/write. (This is apparently a free-for-non-commercial-use PNG library, but its license is rather confused. It claims to be distributed under the terms of the GNU General Public License but includes no source code and has some sort of 30-day evaluation period; the web page also indicates that only GPL'd programs may use it freely. No info on JDK requirements.)

• JIMI [Activated Intelligence / Sun Microsystems] (Java) - all versions; read/write; freeware (formerly commercial). (This is an image toolkit supporting a number of formats, including PNG, either "natively" or via Java's ImageProducer / ImageConsumer model. PNG support was originally based on Jason Marshall's PNGImageProducer source code. JIMI was acquired by Sun in mid-August 1999.)

• JIU / Java Imaging Utilities [Marco Schmidt] (Java 1.1+) - version 0.12.0 and later; read/write; 16 bps support; tEXt, pHYs, and tIME support; no transparency support; freeware (GPL) with Java source. (This is an image-processing library with a number of image-manipulation features.)

• jPDFImages [Qoppa Software] (Java) - all versions; read/write; commercial. (This is a PDF-processing library that can import PNGs into PDF docs and export PDF pages as PNG images.)

• Jun for Java [AOKI Atsushi, ODA Tomohiro, et al.] (Java) - version 316 and later; read-only? requires JIMI or JAI; freeware (GPL) with source. (This is an OpenGL-based "graphic multimedia library with topology and geometry." There is also a Smalltalk version, but it is unclear whether that version supports PNG.)

• JVG / Java Vector Graphics [Faidon Oy-Ab] (Java) - version 1.0 and later; read/write (write-only in 1.0 beta 1); shareware, but 1.0 beta 1 is still available and freeware, and PNG support will be free "soon" (possibly as part of the Java Image Saving package).

• Kylix [Borland] (Linux/X) - all versions; read/write; commercial/freeware. (Kylix's native PNG support apparently is fairly well hidden, but Chris Rorden has documented the procedure to register the format. He also has a link to Peter Haas's page of Delphi PNG and MNG libraries.)

• lcms [Martí Maria Saguer] (Win32, Unix, etc.) - version 1.03 and later; freeware (LGPL) with source. (This is a small, independently developed color management system with read-only support for a "wide subset" of ICC profiles. Originally it was not in any way specific to PNG, but versions since 1.03 can read embedded ICC profiles in PNG images [iCCP chunk].)

• LEADTOOLS [LEAD Technologies] (Windows 3.x, Win32) - various versions from 1997 and later; read/write; no 16-bit-per-sample color support; no 2-bit support; full 8-bit alpha support; commercial. (This is a programming library supporting the compression and decompression of numerous image formats; it also comes in Visual Basic and ActiveX flavors. At one time it supported DOS and OS/2, but there was no sign of either as of October 1998.)

• libAfterImage [Sasha Vasko] (Unix/X) - all versions? read/write (read-only prior to version 0.81); full alpha support claimed; requires libpng and zlib; freeware (GPL) with source. (This is an "image-loading, storing, blending, rendering and manipulation library for X"; claimed to be fast.)

• libferris [Ben Martin] (Unix/X) - version 0.4.0(?) and later; read-only; alpha support; requires libpng and zlib; freeware (GPL) with source. (This is a C++ virtual-filesystem implementation with support for OS/2-like extended attributes [EAs] about files. PNG support is in the form of EA metainfo.)

• libgraph [JP Rosevear] (Unix, etc.) - all versions; write-only; requires gd, libpng, and zlib; freeware (GPL) with source. (This is a programming library that provides "generic graph-building capablities." The original web page claimed that it supported only Unix-like systems, but it should be generic enough to compile under Windows or most other OSes, too. This product is no longer under development.)

• libmng [Gerard Juyn] (Unix, Win32, etc.) - all versions; read/write; MNG and JNG support; requires zlib and optionally libjpeg (JNG) and lcms (color correction); freeware (zlib/libpng) with source. (This is the official MNG/JNG reference library, and it includes PNG support, too. The CVS tree is browsable online. There is also a MASM32 add-on available from the download page.)

• libplot [Robert S. Maier and others] (Unix, etc.) - version 2.4.1 and later; write-only; binary transparency support (alpha support coming); requires libpng and zlib; freeware (GPL) with source. (This is a plotting/graphing library similar to gd above except oriented toward vector drawing rather than raster. It is part of the GNU plotutils package, which is listed on the scientific / graphing apps page.)

• libpng [Guy Eric Schalnat, Andreas Dilger, Glenn Randers-Pehrson, and others] (many) - all versions; requires zlib (below); freeware (BSDish) with ANSI C source. (This is the official PNG reference library. It is used by virtually all freeware and shareware PNG-supporting applications and in many commercial apps. A Visual Basic interface/module is separately available [under Sample Code: VB Standard Modules].)

• libpr0n [Pavlov, tor, saari, et al.] (many) - all versions; read-only; MNG and JNG support; requires libmng, libpng, and zlib; freeware (MPL) with C++ source. (This is a variant of and possible successor to Mozilla's imglib, specifically designed "to render pornographic images in an efficient way." Source code is available from Mozilla's CVS tree.)

• libwmf - see wmftopng on the converters page

• List & Label [combit] (Win32) - version 10(?) and later; write-only? commercial. (This is a "report generator," apparently designed to plug into various database engines and produce reports of some sort. It is reported to have PNG support, though there is no indication of this on the web site.)

• LodePNG [Lode Vandevenne] (many) - all versions; read/write; freeware (BSD/X11/zlib) with C source. (This is a completely standalone PNG encoder/decoder implementation; it requires neither libpng nor zlib. It includes a C++ wrapper.)

• Magma - see Reachin API below

• Mirage Image Library [Paul Legan] (Win32) - all versions; read/write; shareware. (This is a library, apparently for Delphi, with basic image import/export and display functions. A companion library, ImageFX [no relation to the Amiga editor], adds image-manipulation functions but has no file support of its own.)

• Mjølner System [Mjølner Informatics] (Win32, Linux, Solaris, Mac PPC) - version 5.2.2(?) and later; read-only? freeware. (This is a graphical programming environment for the object-oriented language BETA. As of version 5.2.2, PNG is the "native Pixmap format," but it's possible that older versions had some level of PNG support, too. Older versions were also available for IRIX and HP-UX.)

• mmiogpng [Giorgio Costa] (OS/2) - all versions; read-only; uses libpng 0.85 and zlib 0.95; 164k. (This is a PNG-reading extension to OS/2's MMPM/2 multimedia subsystem, much like an Amiga datatype or a BeOS translator. Version 0.7 beta appears to be the first and only release. Also available via ftp: US, Italy).

• MNG Translator [YNOP Talton] (BeOS x86) - version 1.4 and later; read-only? MNG and JNG support; uses libmng, libjpeg, and zlib; freeware with source (on request). (This is an add-on to the BeOS Translation Kit; it supports MNG, JNG and optionally PNG. The German download page is here.)

• MST Image [Yurij S. Musatenko] (DOS, Windows 3.x, Win32, OS/2, Unix) - version 3.3(?) and later; read/write; discards alpha/transparency information; uses libpng and zlib; freeware with source. (This is a multi-platform C++ library. As of mid-1999, the library was available as both a freely downloadable, non-commercial-use version and as a paid, commercial version; only the latter included PNG support. As of March 2000 [version 3.34], the library is completely open-source.)

• Multimedia Conversion Library / MCL [Gromada.com] (Win32) - version 2.0.0(?) and later; read/write; commercial. (This is a conversion library for various image, video and audio formats. PNG is supported, but MNG is not [as of version 2.3.2].)

• NCTImageStudio [NCT Software] (Win32) - all versions? read/write; shareware. (This is a set of ActiveX controls for image conversion and manipulation. It supports Visual Basic, MSVC++, Borland C++ Builder, Delphi, etc.)

• NexgenIPL [Binary Technologies] (Win32) - all versions; read/write; freeware. (This is an image-processing library for MSVC++. It supports multiple image formats and image-manipulation capabilities, and it includes several demo apps.)

• Olectra Chart - see ComponentOne Chart above

• OpenGL::Image [POGL Team / Graphcomp] (Perl) - all versions; read/write; requires ImageMagick, libpng and zlib; freeware (Artistic) with source. (This is an imaging component that can load PNGs for use as OpenGL texture maps and frame-buffer objects and that can save OpenGL frames in PNG format. It is part of the Perl OpenGL [POGL] project.)

• PaintLib [Ulrich von Zadow] (DOS, Windows 3.x, Win32, Unix, etc.) - version 1.3 and later; read/write. (This is a portable "C++ class library for image file decoding and manipulation. It currently supports the PNG, TGA, TIFF, JPEG/JFIF, Windows BMP, and Mac PICT formats." Version 2.0 adds an ActiveX control. PaintLib is available with full source code and ready-to-go makefiles for DOS, Win32 and SunOS; sources for the ActiveX control only compile under Win32, of course.)

• PalmPng [Michal "selmi" Seliga] (Palm OS) - all versions; read-only; requires libpng and zlib; freeware (zlib/libpng license) with C source.

• Panda [Michael Still] (Unix, Win32, etc.) - version 0.4 RC2 and later; read-only (write support in the sense that PDF files support PNG internally); uses libpng and zlib; freeware (GPL) with source. (This is a library for generating PDF files.)

• Photogenics PNG loader/saver [Jolyon Ralph] (Amiga) - version 0.9; read/write; uses libpng and zlib; read-only support for grayscale/monochrome and interlacing; 43k. (This is a "GIO" plug-in for Photogenics 1.2 only. Versions 2.0 and later include native PNG support; see the image editors page for details. Click here if link breaks.)

• PHP [PHP Development Team] (Unix, Win32) - version 3.0.13 and later; read/write; uses gd, libpng and zlib; freeware (BSDish) with source. (This is called a "hypertext preprocessor," but it's really a server-side programming language that can be embedded within web pages. It supports reading PNGs for their dimensions and creating PNGs dynamically. See also Apache Toolbox on the miscellaneous apps page.)

• PIL - see Python Imaging Library below

• PiXCL Tools [VYSOR Integration] (Win32) - version 4.0 and later; read-only; shareware. (This is an "interpreted image-processing and graphics language toolkit" for creating multimedia presentations, demos and imaging applications, especially for satellite data. It incorporates an updated version of Ursus Computing's Imagery, which was once a standalone product [above]. The API for the PiXCL DLL is also available.)

• PixelGraphicLibrary [Peter Beyersdorf] (Win32) - all versions; read/write; shareware. (This is an image-manipulation library specifically for use with Delphi 2 and 3; it can read and write PNG images. It also includes a simple demo viewer. This product has been discontinued.)

• PLplot [Maurice J. LeBrun / Geoff Furnish / Alan W. Irwin] (Unix) - version 5.0.3 and later; write-only; requires libpng and zlib; freeware (LGPL) with source. (This is a "library of C functions that are useful for making scientific plots from programs written in C, C++, Fortran, Octave, Python, and Tcl/Tk.")

• png++ [Alexander Shulgin] (many) - all versions; read/write; requires libpng and zlib; freeware (BSD) with C++ source. (This is a C++ interface to libpng with an emphasis on simplicity and ease of use.)

• PNG DataType #1 [Cloanto] (Amiga) - all versions; read-only; 8-bit only prior to version 43.2 (24-bit tag extensions supported in 43.2 and later); transparency support; includes sample DataType-based image viewer (ViewDT) with source code; 67k. (A datatype is a standardized DLL-type thing that allows any image-handling application under AmigaOS 3.0 or later to understand PNG images automagically, without recompilation. Also see Personal Paint on the image editors page. Click here if link breaks.)

• PNG DataType #2 - see akPNG.datatype above

• PNG DataType #3 - see WarpPNG.datatype below

• PNG DataType #4 [Gunther Nikl] (Amiga) - all versions; read-only; for OS 3.0 and later; transparency support; gamma support; uses libpng and zlib; freeware (for non-commercial use) with source; 140k. (Click here if link breaks.)

• PNG DataType #5 - see vPNG.datatype below

• PNG Delphi / TPNGImage [Gustavo Daud] (Win32) - all versions; read/write; full alpha support (including single-shade/color transparency in grayscale and RGB images as of version 1.428); gamma support; interlacing support (write) as of version 1.42; text support; includes zlib compiled object files and Pascal wrapper; freeware with source. (This is a Delphi 5 [Pascal] component for loading and saving PNG images, with multilingual error messages [English, Portuguese and German]. Older copies of the code are available from various Delphi freeware sites. See also TNGImage below.)

• PNGDIB [Jason Summers] (Win32) - all versions; read/write; full alpha support in version 2.0.0 and later; full gamma support; requires libpng and zlib; freeware (BSD) with source. (This is primarily a "mini PNG/DIB conversion library" with two functions: one for converting PNG to DIB, and one for the reverse. Versions 1.1.0 and later also include a simple PNG viewer as a sample app.)

• PngEncoder [J. David Eisenberg] (Java) - all versions; write-only; 32-bit alpha support; requires JDK 1.1 (PngEncoder) or JDK 1.2 (PngEncoderB); freeware (LGPL) with source.

• PNGgraph.pm [Steve Bonds] (Perl) - version 1.10 and later; write-only? freeware (Artistic) with source. (This is a Perl module to draw bar, line and pie charts in PNG format. It is based on Martien Verbruggen's GIFgraph 1.10 and requires Lincoln Stein's GD.pm. Judging by the CHANGES file, this version appears to predate Dmitry Ovsyanko's port [below] by about three weeks.)

• PNGgraph.pm [Dmitry Ovsyanko] (Perl) - version 1.11 and later; write-only? freeware (Artistic or GPL) with source. (This is a Perl module to draw bar, line and pie charts in PNG format. It is "98% based" on Martien Verbruggen's GIFgraph 1.20 and requires Lincoln Stein's GD.pm. This was apparently developed independently of Steve Bonds' port [above], despite having the same name and version number.)

• PNGHack [Sean M. Foy] (Win32) - all versions; "read/write"; "alpha support"; freeware (LGPL) with source. (This is a "collection of ASP.NET Web Custom Controls for rendering cross-browser image references in HTML." Specifically, it's a server-side method of providing normal browsers with normal HTML but MSIE/Windows with the proprietary DirectX/CSS extensions it requires in order to render PNG transparency correctly. [Hence "hack."])

• PNGHandler [Simon Clarke] (BeOS) - all versions; read/write; full alpha support? no 16-bps support; freeware. (Older versions require Jon Watte's BeOS Datatypes library [239K], but current releases use the Be Translation Kit. PNGHandler may have been renamed to PNGTranslator as of version 1.20.)

• PNGImageProducer [Jason Marshall] (Java) - version 0.88 (final public release) and earlier; requires java.util.zip (a.k.a. zlib 1.0.4) from JDK 1.1 or later; freeware with source; 55k. (Sun's JIMI is partly based on this.)

• PNG_IO [Steve Sangwine] (many) - all versions; read/write; requires zlib; freeware (GPL) with source. (This is a basic, high-level Ada 95 package for reading and writing PNG files. It is neither a clone of nor a wrapper for libpng; for example, versions prior to 3.3 did not support writing interlaced images, though they could read them. PNG_IO can write gamma, sRGB, and several other ancillary chunks.)

• Pnglets [Roger E. Critchlow, Jr.] (JavaScript) - all versions; write-only; freeware (GPL) with source. (This is a PNG drawing library written in JavaScript [not Java!]; it can be used to create client-side line drawings on the fly, without either libpng or zlib. Pnglets was inspired by and is partly based on algorithms in the gd library above, but the package draws from other sources as well and predates gd's PNG support.)

• PNGLIB [Edmund H. Hand, Uberto Barbini, Eric Engler] (Win32) - all versions; read/write; requires libpng and zlib; freeware with source code. (This is a Delphi wrapper for libpng and zlib. It appears to have a bug in writing the PNG IEND chunk [failure to include the length field], though this is strange given its use of libpng.)

• PNGlib [Thomas Kabir] (Win32) - all versions; read-only; full alpha support; freeware with Visual Basic source. (This is primarily a sample viewer, PNGView, that apparently can composite a transparent PNG image against a background image; but it also includes complete source code for a VB PNG-decoding library, PNGlib.)

• pnglite [Daniel Karling] (many) - all versions; read/write as of version 0.1.17 (earlier versions read-only); requires zlib; freeware (zlib/libpng license) with C source. (This is a lightweight substitute for libpng.)

• PngUnit [Edmund H. Hand, Jack Goman] (Win32) - all versions; read/write; freeware with source. (This is another Delphi wrapper for libpng and zlib based on Edmund Hand's PngImage.pas. It apparently includes a viewer with BMP-to-PNG conversion capability.)

• PNGwriter [Paul Blackburn] (any) - all versions; read/write; 16-bit-per-sample support; requires libpng and zlib; freeware (GPL) with source. (This is a C++ class for plotting XY data and drawing basic shapes directly to a PNG file. It includes HSV conversion functions, documentation in both English and Spanish, etc. It's also available from SourceForge.)

• PowerDoc [D-Type] (Win32) - all versions? read/write; commercial. (This is a vector-based graphics library for creating and rendering "professional, high-quality, and resolution-independent documents of any kind." It can import and export PNG images. An ASP variant can do [web] server-side rendering for IIS Active Server Pages.)

• PrinterCE [FieldSoftware] (Windows CE 3.x) - version 2.0(?) and later; read-only; commercial. (This is a PNG-supporting printing module for WinCE 3.x, a.k.a. Pocket PC. The toolkit is also available for older WinCE platforms, but without PNG support.)

• Pygame [Pete Shinners] (Win32, Mac OS, Mac OS X, BeOS, Unix) - all versions? read/write? full alpha support? requires SDL, libpng and zlib; freeware (LGPL) with source. (This is a Python-based multimedia library/toolkit written on top of SDL. It is primarily used for games, although there are also image viewers and other applications written with it.)

• Python Imaging Library [Secret Labs AB / Fredrik Lundh] (Unix, Win32) - version 0.2b3 (read-only) and later; read/write in version 0.2b4 and later; requires zlib; freeware (BSDish) with source. (PIL is an image-manipulation library for the Python interpreted programming language, with extensive file-format support and a powerful Image class supporting lots of image manipulation and processing methods, including stuff for on-the-fly image generation. It can also support Tcl / Tk if the tkinter package is installed, and it may once have supported Mac OS.)

• QHTM [GipsySoft] (Win32) - all versions; read-only; no transparency support. (This is Russell Freeman's "Quick, Light HTML Control"; it allows one to display a subset of HTML within an application. PNG is the only image format currently supported.)

• Qt [Trolltech] (Unix/X, Win32, BeOS x86) - version 2.0 and later, or version 1.4x with the Qt Image IO Extension Library (commercial only); read/write? MNG and JNG support (read-only?) as of version 2.2.0; uses libmng, libjpeg, and zlib; freeware (Free Edition: QPL) or commercial (Professional Edition) with source. (This is a C++ GUI toolkit, perhaps best known for its use in KDE under Linux.)

• QuickTime [Apple] (Mac PPC/68k, Win32) - version 3.0 and later; read/write as of 4.0; full gamma support; full alpha support; breaks Internet Explorer's handling of standalone PNGs on Mac OS X (quick fix); uses zlib; freeware. Also version 2.5 for Macintosh with Sam Bushell's QuickTime PNG-Importer; read-only. (This amounts to a PNG plug-in for Mac and Windows apps; it allows any application that knows about QuickTime graphic importers--even SimpleText--to read PNG files and, as of version 4.0, write them (presumably). Note that the alpha support does not extend to QuickTime's use as an old-style Netscape plug-in. The included PictureViewer app can be used to view and convert PNG images.)

• RasterMaster [Snowbound Software] (Win32, Java, Unix, Mac OS, Mac OS X) - version 7.0(?) and later; read/write; commercial. (This is an imaging toolkit with with support for multiple platforms and languages, including C/C++, Java, and ActiveX.)

• RbPNGLib [Noriyuki Horiuti] (Mac PPC) - all versions; read/write; alpha support; gamma support; text support; requires libpng and zlib; freeware with C++ source. (This is a plug-in for REALbasic 2.1 through 3.x; it allows REALbasic programs to read and write PNGs.)

• Reachin API [ReachIn Technologies] (Windows NT, IRIX/X) - all versions; read/write; alpha support (read/write but not display); commercial. (This is a 3D API/toolkit for developing "multisensory"--at a minimum, visual and haptic--3D applications. PNG is the "primary native graphics format." It was formerly known as Magma.)

• Simple DirectMedia Layer [Sam Lantinga] (Linux, Win9x/NT, BeOS, Mac) - version 0.10 and later; read-only; uses libpng and zlib; freeware. (This is a "free, cross-platform, multi-media development API." It is used in a number of games, including Hopkins F.B.I., Civilization: Call To Power, Myth II: Soulblighter, and others. PNG support is indirectly provided by the ImgLib demo in the accompanying demos/examples archive. Philippe Lavoie wrote the PNG decoder code on which the ImgLib example is based.)

• Sixlegs Java PNG [Six-Legged Software] (Java) - all versions; read-only; freeware (LGPL) with Java source. (This is Chris Nokleberg's Java 1.1 PNG package, including source code. Version 0.6 supported transparency, gamma correction, progressive display, grayscale conversion, etc. Version 0.7 added support for sRGB, iCCP, and private chunk-handling. Version 0.8 added support for oFFs, pCAL, sBIT, sCAL and sPLT. Version 0.9 reduced memory usage and added support for iTXt. Version 1.0[a] was the first version released with full source code under the LGPL and included a workaround for a bug in IE4 and IE5. Version 1.1 added support for gIFg and gIFx. Write support is now planned for a separate package.)

• Squeak [Apple Computer / Squeak Central] (Mac OS, Mac OS X, Unix/X, Win32, RISC OS, BeOS, OS/2, DOS, etc.) - version 3.0(?) and later; read/write? freeware with source. (This is a graphical programming environment for the object-oriented language Smalltalk-80. It includes a full complement of 2D image capabilities, including PNG support.)

• SuperView Library [Andreas Kleinert] (Amiga) - version 15.0(?) and later; read/write; shareware. (This is part of the SViewII application package, formerly called SuperView; the library reads and writes many image formats.)

• THBImage Professional Edition [THBComponentware] (Win32) - all versions; read/write as of version 2.0 (previously read-only); alpha support as of version 2.0; commercial. (This is a set of ActiveX components with various image-manipulation capabilities, including scaling and compositing, for use with VC++, Visual Basic, and MS Access. PNG is one of the supported raster formats. Note that the Standard Edition does not support PNG.)

• TIFFY Toolkit [Art & Computer Hackbarth] (Java) - all versions; read-only; shareware. (This is a Java image-viewing toolkit with support for PNG, TIFF, GIF, JPEG and BMP and reportedly a small memory footprint. A demo viewer, TIFFY View, is also available via the viewers page.)

• Titan [Dan Brown] (Linux, Win32) - all versions? read/write; freeware. (This is a "portable image handler for OpenPTC." It is distributed as C++ source code.)

• TNGImage [Gerard Juyn, Scott Price, Peter J. Haas] (Win32) - all versions; read/write; MNG and JNG support; uses libmng, libjpeg, lcms, and zlib; freeware (zlib/libpng) with Pascal source. (This is a Delphi 3/4/5/6 component for loading and saving PNG, MNG and JNG images. libmng.dll, containing all four required libraries, is included. Linux/Kylix support is coming in version 1.2.)

• Translation Kit - see BeOS on the miscellaneous apps page

• TwistedPixel [Bananas Software] (Win32) - version 0.9 and later; read/write. (This is an ActiveX control [OCX] for display/conversion/editing of various image formats. It can be used with Visual Basic, Visual C++, Access, Delphi, etc.)

• uf2png.fio [Ulead Systems] (Windows 3.x) - all versions; read/write; freeware; 79k. (This is an add-on module for all Ulead image products [including Ulead Viewer on the image viewers page] and for Adobe/Aldus PhotoStyler [on the image editors page]. There may be a newer version on Ulead's very slow ftp site; the version above is the first non-beta release, v1.1, dated 15 September 1995 internally and 10 January 1996 on the ftp site.)

• UltraWebSuite [Infragistics] (Win32) - all versions? read/write? commercial. (This is a suite of server-side forms controls for ASP.NET; PNG is supported in the UltraWebChart and UltraWebNavigator components.)

• UltraWinSuite [Infragistics] (Win32) - all versions? write-only? commercial. (This is a suite of forms components for .NET; PNG is supported in the UltraWinChart, UltraWinTree, and UltraWinListBar components.)

• Victor Image Processing Library [Catenary Systems] (Windows 3.x, Win32) - version 5.0 and later, or version 4.x with a separate add-on; read/write; no alpha support (only single-color/GIF-like transparency); commercial. (This is a Windows DLL that can read and write various image formats. Apparently only the Win32 version is still under development; the last 16-bit Windows release was 4.25, and the DOS static library has never been updated past version 3.7.)

• Virtual Print Engine [IDEAL Software] (Win32) - all versions; read/write; commercial. (This is a toolkit and API to create electronic documents; it can both import and export PNG images, although the primary output format is PDF. Of the five flavors, PNG is supported in all but the lowest [Standard]. The site is available in German, too.)

• vPNG.datatype [Viktar Pakhomau/Victor Pakhomov] (Amiga 68k) - all versions; read-only; for OS 3.0 and later; broken interlaced support; freeware for non-commercial use; 11k. (This is very closely related to the vPNG viewer on the viewers page. Click here if link breaks.)

• WarpPNG.datatype [Oliver Roberts] (Amiga 68k/PPC) - all versions; read-only; supports 68k, WarpOS and MorphOS; alpha support; gamma support; uses libpng and zlib; freeware.

• Watchdog png library [Gerald Roehrbein] (Unix, etc.) - all versions; write-only? requires libpng and zlib; freeware (GPLv2) with C source. (This is a library to generate PNG images on the fly; it was created as part of the Watchdog web-statistics package, can write directly to an HTTP port, and is designed to be very simple to use. It is partly based on PNGwriter [above].)

• wimg [Yudong Yang] (Win32) - all versions; read/write? full alpha support? requires libpng and zlib; freeware with source code; 179k. (This is a multi-format image-processing library. A README file is available, and the archive also may be downloaded here.)

• WinSView [Andreas Kleinert] (Win32, Linux) - all versions; read/write; uses libpng and zlib; shareware. (This is a C++ class library with an MFC GUI front end [Windows version]; it is a port of the Amiga SuperView Library above. The class library is generic and may be ported to other platforms such as BeOS and QNX.) (coming)

• wv [Caolán McNamara] (Unix, Win32, Amiga, VMS, OS/2) - version 0.4.0 and later; read/write? requires libpng and zlib (and optionally ImageMagick); freeware (GPL) with source. (This is a library to read and parse Microsoft Word documents, versions 6 through 9 [a.k.a. 6, 95, 97, 2000]. It also goes by the name wvWare and was formerly known as mswordview.)

• wxWindows [wxWindows team] (Win32, Unix/X, Unix/GTK+, Unix/Motif, Mac OS, Mac OS X, OS/2) - version 2.0 and later; read/write? uses libpng and zlib; freeware (LGPLish) with source. (This is a cross-platform C++ GUI toolkit. Subprojects include wxPython.)

• XmHTML [Ripley Software Development] (Unix/X) - all versions; read-only; full gamma support; full