Gnulib, the GNU portability library, offers a macro system and C declarations and definitions for commonly-used API elements and abstracted system behaviors. It can be used to improve portability and other functionality in your programs. Gnulib takes a different approach than libiberty. Gnulib components are intended to be shared at the source level, rather than being a library that gets built, installed, and linked against. Thus, there is no distribution tarball; the idea is to copy files from Gnulib into your own source tree. However, there are bimonthly stable snapshots of the Gnulib codebase published at http://erislabs.net/ianb/projects/gnulib/