Today I wrote a free/open disasm engine for Microsoft’s Intermediate Language (MSIL).
http://ntcore.com/Files/disasmsil.htm
You can use it any context you wish. There are no license restrictions. The only thing I ask you to do is to send me your bug fixes (if any).
I also added the MSIL disasm engine to the CFF Explorer which is now able to disassemble the methods’ code directly from the MetaData tables.