The source headers are usually a good place to look for documentation and examples.

High-performance dynamic arrays Documentation array.h array.c	Cross-platform directory handling Documentation dir.h dir.c	Cross-platform dynamic library handling Documentation dll.h dll.c
General purpose logging facility Documentation log.h log.c	General purpose plug-in management facility Documentation plugin.h plugin.c	MS style Sleep() for other systems Documentation sleep.h sleep.c
Hash map with string based keys Documentation strhmap.h strhmap.c	General purpose facility for measuring elapsed time inside code Documentation timer.h timer.c