LibU is a multiplatform C library that comes under a BSD-style license. It includes many interdependent modules for accomplishing several tasks: memory allocation, networking and URI parsing, string manipulation, debugging, and logging in a very compact way, plus many other miscellaneous tasks. It has a small footprint (about 70KB for the default configuration), it is modular, and it has a multiplatform nature, making it an ideal candidate for embedded systems. KLone is an example of such usage.
Libporty provides a higher level API for some commonly used library functions such as sockets, date/time, file system access, background processes, and asynchronous DNS resolving. Libporty is configured using scconfig and the API is guaranteed to work the same way on all supported systems. An application that exclusively uses the libporty API will not require autotools/scconfig for porting. Libporty has been tested on Linux, Windows, Mac OS X, multiple BSD variants, Minix, OpenSolaris, and some ancient Unix systems.