yuck is a command line option parser for C that works on a minimal set of dependencies - only a C compiler and the m4 macro processor are required. It supports all the standard use cases: GNU-style long options (--option), condensable short options (-xab for -x -a -b), and optional arguments to long and short options (--foo[=BAR]), multiple occurrence of options (-vvv). Most importantly, it does not depend on libc's getopt() nor getopt_long().
dhcpy6d delivers IPv6 addresses for DHCPv6 clients, which can be identified by DUID, hostname, or MAC address, as in the good old IPv4 days. Addresses may be generated randomly, by range, or by arbitrary ID or MAC address. Clients can get more than one address, leases and client configuration can be stored in databases, and DNS can be updated dynamically.
libusbx is a library which provides generic access to USB devices. As a library, it is meant to facilitate the development of applications which communicate with USB hardware. Its main features are portability (a single cross-platform API for Linux, OS X, Windows, and *BSD), user-mode (no special privileges required), and USB version-agnosticism (all versions of the protocol supported, including USB 3.0).
METAXPON ("Metachron" in Greek letters) is a small and fast audio DSP library for time-scale manipulation of 16-bit integer or 32-bit floating point stereo audio data streams. It employs a rigid phase-locked vocoder with dedicated transient detection and processing, and can work in real-time or non-real-time. Four editions are included - a portable edition and three x86 editions. The portable edition can be built with any ANSI C compiler and is OS- and architecture-independent. The three x86 editions are written in assembly using the FPU, 3DNow!, and SSE instruction sets, respectively, with automatic selection between them depending on the CPU capabilities. They can be compiled with MASM, JWASM, or NASM, producing libraries of object files in 8 formats.