Info-ZIP portable compression/archiver utilities (Zip, UnZip, WiZ, etc.)
IRE is a tile-based Computer Role-Playing Game engine based on Ultima 6, but with an emphasis on customisation and cross-platform support. Everything is controlled using scripts.
An IRC client that uses Tcl for not only the scripting, but also the "glue" at the C level for how all the parts of the application fit together.
Al2 is a language, close to C++ and Java, designed for use in mathematics and science, but is procedural unlike Mathematica and Maple. Like C++, class operators can be defined. Like Java, there is no need for header files. Aled is an interface to AL2.
Fast and efficient self-assembling 80x86 assembler for DOS/Win32/Linux; with 8086-80486/Pentium/MMX/SSE/AVX/XOP instructions support, 16-bit/32-bit/64-bit code, binary/MZ/PE/COFF/ELF output formats.
Spice+ is a general-purpose circuit simulation program, based directly on SPICE 3F.5 from the University of California (Berkeley). An improved version of Spice for DOS, Windows and Linux. http://spicep.sourceforge.net
Common Hardware Recovery Solutions by Ukrainian-Russian network from http://hardw.net/forum
KewlWrite is a word processing program built for Linux and other systems that has a much wider variety of document setups than other text programs. For example, with KewlWrite, you can code an RSS page or write a page in PHP.
A tile based game engine for Windows/DirectX designed to simulate the best features of Super Mario Bros. 1, 2, and 3, while adding a map / entity editor and networked play.
The UniXML library is intended to be an extremely portable XML DOM parser library, completely OS and C compiler independent.