This is a ISRO GSLV Mk I/II developed mainly to launch satellites in GTO. This add-on comes with a powerful programmable guidance unit (read GSLV User's Guide in Doc folder). Also, this add-on allows for user configured payload.
The module DLL is compiled using VC++ 2005 express so you might need Microsoft .NET framework Version 2.0 distributable Package from www.microsoft.com/downloads/details.aspx