Hotpatch is a library that can be used to dynamically load a shared library (.so) file on Linux from one process into another already running process without affecting the execution of the target process. The API is a C API, but also supported in C++. The user can load his/her own .so file into an already running process, invoke a custom symbol/function in that .so file, and pass arguments to that function as long as it is serialized to the form of a byte buffer and length of the buffer.
PFFFT is a very small 1D Fast Fourier Transform library based on the venerable FFTPACK v4. It handles single precision real and complex transforms. Computations take advantage of SSE1 instructions on x86, Altivec on PowerPC, and NEON on ARM, allowing it to achieve a performance level that is not too far from the very best FFTs (FFTW, Intel MKL, Apple vDSP).
GammaMOO is a fork of the LambdaMOO server with numerous cleaned-up patches and modern MOO functionality. This currently includes multicore support, object caching and other acceleration features, enhanced file I/O, UTF support, new built-in data types, and stability improvements with 64-bit support in progress.