Very beta beta gacutil.exe Help is still placeholder, use: /i for install. Example: (/i /path/to/assembly.dll) /u for uninstall Example: (/u assembly) /l for listing Example: (/l) Wont work if your prefix isnt /usr and /usr/lib/mono/gac isnt created. Not all potential error paths/exceptions are caught. This is just mainly being put into cvs to get it off my somewhat instable hard drive and under revision control. This code is also ugly, and nasty, I wrote most of it over the course of about an hour, if not less.