Brace is a dialect of C that looks like Python. Brace has coroutines, hygenic macros, header generation, #! scripting and cached executables, and libraries with graphics and sound.
Zimbu is an experimental programming language. It is a very practical, no-nonsense kind of language. It mixes the good things of many existing languages and avoids their deficiencies. And then throws in a few brand new ideas.
ooc is a modern, object-oriented, functional-ish, high-level, low-level, sexy programming language. it's translated to pure C with a source-to-source compiler. it strives to be powerful, modular, extensible, portable, yet simple and fast.
OpenCTM is a file format and a software library for compressed 3D triangle meshes. The geometry is compressed to a fraction of comparable file formats (3DS, STL, VRML...), and the format is easily accessible through a simple, portable API.
Tokyo Cabinet is a library of routines for managing a database. The database is a simple data file containing records, each is a pair of a key and a value. Every key and value is serial bytes with variable length. Both binary data and character string can be used as a key and a value. There is neither concept of data tables nor data types. Records are organized in hash table, B+ tree, or fixed-length array.
Open Asset Import Library is a free C/C++ library to import various well-known 3D model formats into applications. The library loads models in a straightforward in-memory format that can be easily read and processed by applications. Various post processing steps can be executed on the imported data to optimize it for a particular purpose.
dbestfit is a complete and fast malloc-replacement that features a best-fit algoritm with special small-block treatment, to maximize memory usage. This is particularly suitable for embedded systems.
The code for this allocator has been placed in the public domain (available from ftp://g.oswego.edu/pub/misc/malloc.c), and is apparently widely used: It serves as the default native version of malloc in some versions of Linux; it is compiled into several commonly available software packages (overriding the native malloc), and has been used in various PC environments as well as in embedded systems, and surely many other places I don't even know about.