tilecacheindex
Tilecacheindex creates shapefiles that can be used as tileindex files for mapserver. The files are created from MGMaps tile cache folders. It is free software released under the terms of the GPL.
Documentation
The documentation is available in different formats: HTML, PDF.
Source Code
The source code is available through the Subversion repository:
https://avpgcon.svn.sourceforge.net/svnroot/avpgcon/trunk/tilecacheindex
TortoiseSVN users can use this checkout link.