The Nebula Device is a free multiplatform game engine currently running under Linux and Windows. It uses OpenGL and/or Direct3D for rendering and Tcl/Tk for scripting. Living C++ objects can be browsed and manipulated at runtime from the builtin console, or remotedly from a minimal terminal based console app. A powerful channel animation system allows any floating point attribute to be animated, and specialized animator classes allow things like realtime bone animation with weighted vertex skin.
tal aligns common characters at the ends of lines. This is especially useful for making long C macro definitions look nice or for repairing "broken" comment boxes. tal works on any kind of common ending, which it autodetects. Intended as, but not limited to being, a filter program ("plug-in") for text editors.
TEA Total is a collection of extremely small encryption tools. At the heart of TEA Total is the TEA (Tiny Encryption Algorithm): a fast and secure 128-bit private key algorithm which was developed and placed in the public domain by David Wheeler and Roger Needham of the Cambridge Computer Laboratory.
Spin Chat is a completely Java based Chat application, both server and client. It has been originally developed on Linux and runs excellent on it. It features vast customization possibilities, multi-channels, built-in spam control, graphical administration tools, I18N, channel logging, ignoring, emotes, etc.
Sizzle is a Scheme interpreter for embedding into C applications and for standalone scripting. It implements a nearly complete subset of R5RS Scheme, adding a lot of primitives for U*ix scripting, regular expression searching, a simple module system, dynamic library linking, powerful string processing procedures, and much more. It includes a user's guide and an embedding manual in texinfo format, some examples, the embedding library, and a standalone interpreter for interactive use and scripting.
RPilot is an interpreter for the IEEE-standard programming language PILOT written in portable C. PILOT is a language that was designed in the 1960's to support computer-aided instruction and is very simple to learn. RPilot comes with an introduction to the language and several examples.