NaviServer, a high performance web server written in C and Tcl
Single sided linked list (kind of lib with test-code, C, C++ and java)
tiny User Level Threads library
Ring-Buffer library in C, includes support of multithreading
Scriptable database and system performance benchmark
RTOS for Secure, Safe and Real-Time Systems
Real time preemptive embedded multi-thread kernel
c/c++ debug-mutex library
CLIPS with lock support. CLIPS for safely handling simultaneous access
Universal programmer/debugger. Universal embedded software framework.