AngelScript is a free, open source, flexible, and cross-platform scripting library meant to be embedded in applications. The purpose is to provide an easy to use library that is powerful, but that isn't weighed down by a large amount of rarely used features.
Development of AngelScript begun in February, 2003, with the first public release on March 28th, 2003, with only the most basic of functionality. Ever since that day the world has seen frequent releases with new features and improvements. The author is still dedicated to the continued improvement and growth of this library.
The official site for the library is http://www.angelcode.com/angelscript.