Generic Libraries
- GNU Libc (Portable POSIX and ISO standard compliant C library. License: LGPL) (cvs) (ml) (manual) (FAQ) (deb)
- OSSP Library Projecst (Large collection of libraries providing: portable threading, network programming abstraction, process management, filesystem abstraction, data management, exception handling, and more. License: GPL/LGPL/BSD-style) (cvs)
- Diet Libc (Lightweight Libc. License: GPL)
- uClibc (Lightweight Libc. Suitable for MMU-less CPU's.) (cvs) (ml) (deb)
- Libowfat (GPL licensed reimplemention of Libdjb, which tries to increase security and portability for several basic libc functions. License: GPL) (deb)
- c2lib (Perl and STL influenced library of general programming tools. License: LGPL)
- libmba (Collection of C functions that can be useful to any project. Included features: hash map, linked list, stack ADTs, a DOM-like interface that can load and store XML files for simple XML processing, and more. License: BSD-style) (source)