Coq au Vin is a blogging engine written in Chicken Scheme. It is designed to appeal to users who have basic Web development skills (i.e., who know HTML and CSS), are able to install their own server-side software, and would rather edit a template than press 105 buttons to customize their sites.
Capstone is a disassembly framework with the target of becoming the ultimate disasm engine for binary analysis and reversing in the security community. Running on Windows, Mac OS X, Linux, FreeBSD, OpenBSD, and Solaris, it can disassemble ARM, ARM64 (ARMv8), MIPS, PPC, and x86 architectures. Capstone provides rich details about disassembled instructions along with useful semantic information.
Suricata is an Intrusion Detection and Prevention (IDS/IPS) engine developed by the Open Information Security Foundation and its supporting vendors. The engine is multi-threaded and has native IPv6 support, file extraction capabilities, and many more features. It's capable of loading existing Snort rules and signatures, and supports many frontends through Barnyard2.
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().
Rodent filemanager is a fast, small, and powerful file manager. Its emphasis is on ease of use for the advanced user, not the computer illiterate. Rodent filemanager (a.k.a. xffm >= 4.6.0) is the next step in the evolution of Xffm, now with a threaded design optimized for multicore processors.
Concurrency Kit provides a plethora of concurrency primitives and lock-less and lock-free data structures designed to aid in the design and implementation of high performance scalable concurrent systems. It was designed to minimize dependencies on operating system-specific interfaces, and most of the interface relies only on a strict subset of the standard library and more popular compiler extensions.