BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
cMySQL_DB is a class that handles MySQL database connections and queries. It can select the database to access, escape literal text values to use in queries, execute arbitrary SQL queries, retrieve query results as arrays or objects, retrieve the count of query result rows, retrieve the number of affected rows, and retrieve the last inserted table record identifier. Errors can also be logged.
spooky-c is a C version of Bob Jenkin's spooky hash. The only advantage over Bob's original version is that it is in C, not C++,'and comes with some test and benchmark code. This is a very competitive hash function, but is somewhat unportable (64-bit little endian only). It's more portable than some of the contenders like CityHash.
SLEEF (SIMD Library for Evaluating Elementary Functions) is a library that facilitates programming with SIMD instructions. It implements the trigonometric functions, inverse trigonometric functions, exponential and logarithmic functions in double precision without table look-ups, scattering from, or gathering into SIMD registers, or conditional branches. This library also includes some functions for evaluation in single precision.
Multi-Sandbox Lua Engine (MSLE) is a modified Lua interpreter which supports creation and maintenance of multiple "100% tight" sandboxes from within Lua. "100% tight" means that the amount of memory used by a sandbox (counting both code and data) is strictly limited, a feature Lua did not offer before.