LibU is a multiplatform C library that comes under a BSD-style license. It includes many interdependent modules for accomplishing several tasks: memory allocation, networking and URI parsing, string manipulation, debugging, and logging in a very compact way, plus many other miscellaneous tasks. It has a small footprint (about 70KB for the default configuration), it is modular, and it has a multiplatform nature, making it an ideal candidate for embedded systems. KLone is an example of such usage.
xlife is a laboratory for experimenting with cellular automata. It supports loadable rulesets and palettes, different topologies, and up to 256-state cellular automata. It has rules and patterns for Life, Brian's Brain, Perrier's Loops, Langton's Ants and Loops, Wireworld, E.F. Codd's 1975 UCC automaton, some Prisoner's Dilemma games, and many others. It is very fast for step-by-step mode, bounded grid, and chaotic patterns. It has several unique features: a historical mode, a pseudocolor mode, and n-state statistics. It has been developed since 1989. The modern version of Xlife began its history in 2011.