SLIRP is a vectorizing code generator aimed primarily at simplifying the process of creating modules for the S-Lang scripting language. It supports making C, C++, and Fortran code callable directly from the S-Lang interpreter and can automatically vectorize functions to take advantage of the abilities of S-Lang. SLIRP can also generate parallelizable wrappers for OpenMP-aware compilers.
Funky is a tiny, embeddable programming language with almost unlimited extending capabilities. It presents itself as a single class that contains the entire interpreter. Two versions of this class exist: Funky::Funky, a floating-point version, and Funky::Groovy, an integer version. You can install your own functions in the language as long as your functions take a vector of the built-in type of the interpreter and return an instance of that built-in type (or a vector of those). Funky is a functional programming language. As such, it treats everything as functions, and those functions handle only one type: double in the case of Funky::Funky, or int in the case of Funky::Groovy.
EDM is a fork of Sauerbraten (http://www.sauerbraten.org/) which is in development but playable. It features several multiplayer game modes like Deathmatch and Instagib, dynamic map model physics, enhanced particle effects, unique weapons and powerups, and more. Maps can be edited with other players online.
Onyx is a powerful stack-based, multi-threaded, interpreted, general purpose programming language similar to PostScript and Forth. It can be embedded as an extension language into other applications, and was designed to have a small memory footprint. It is among the smallest embeddable interpreters available.