GD library is an open source code library for the dynamic creation of images by programmers. GD is written in C, and wrappers are available for Perl, PHP and other languages. GD creates PNG, JPEG and GIF images, among other formats. GD is commonly used to generate charts, graphics, thumbnails, and most anything else, on the fly. While not restricted to use on the web, the most common applications of GD involve website development. gd is a graphics library. It allows your code to quickly draw images complete with lines, arcs, text, multiple colors, cut and paste from other images, and flood fills, and write out the result as a PNG or JPEG file. This is particularly useful in World Wide Web applications, where PNG and JPEG are two of the formats accepted for inline images by most browsers. gd is not a paint program. If you are looking for a paint program, you are looking in the wrong place. If you are not a programmer, you are looking in the wrong place, unless you are installing a required library in order to run an application. gd does not provide for every possible desirable graphics operation. It is not necessary or desirable for gd to become a kitchen-sink graphics package, but version 2.0 does include most frequently requested features, including both truecolor and palette images, resampling (smooth resizing of truecolor images) and so forth. What if I want to use another programming language? Not all of these tools are necessarily up to date and fully compatible with 2.0.33. PHP A variant of gd 2.x is included in PHP 4.3.0. It is also possible to patch PHP 4.2.3 for use with gd 2.0.33; see the gd home page for a link to that information. It would be a Good Idea to merge all of the things that are better in mainstream gd and all of the things that are better in PHP gd at some point in the near future. Perl gd can also be used from Perl, courtesy of Lincoln Stein''s GD.pm library, which uses gd as the basis for a set of Perl 5.x classes. Highly recommended. OCaml gd can be used from OCaml, thanks to Matt Gushee''s GD4O project. Tcl gd can be used from Tcl with John Ellson''s Gdtclft dynamically loaded extension package. Pascal Pascal enthusiasts should look into the freepascal project, a free Pascal compiler that includes gd support. REXX A gd interface for the REXX language is available. Any Language The fly interpreter performs gd operations specified in a text file. You can output the desired commands to a simple text file from whatever scripting language you prefer to use, then invoke the interpreter.