pkg-config is a system for managing library compile/link flags that works with automake and autoconf. It replaces the ubiquitous *-config scripts you may have seen with a single tool.
Release Notes: Lib flags are now kept in context. Aggressive removal of duplicate arguments was scaled down. An old bug preventing circular requires was fixed. Many corner case bugs and some ambiguous behaviors were eliminated. Other minor modifications and fixes were made.
Release Notes: The check for the POSIX shell used in tests has been improved. The integration of the internal Glib has been improved. Other minor bugs have been fixed.
Release Notes: Many fixes and enhancements were made.
Release Notes: Segfaults were fixed. Win32 fixes were made. The --short-errors option was added, and is now used by pkg.m4 if available. This gives a better error message if some libraries can't be found.
Release Notes: A bug was fixed. The project is now called pkg-config rather than pkgconfig.