In 2006 Microsoft released a modified version of the source code along with most game assets (i.e. everything needed to compile the game without networking support and without all the art) under a Shared Source licence in order to demonstrate its XNA Build system. Source is available from Microsoft's downloads site.
Featuring dozens of screenshots, 'Mech renders, concept art, and more, this fan site kit a great way to help jump start a MechCommander 2 fan site - or round out an existing one.