from your commercial offerings of Core Impact, CANVAS et al, the one
open source product that should immediately spring to mind is
Metasploit, created by HD Moore. This tool has a number of
precompiled exploits and can be run in a number of differing formats,
scripted, command-line and graphical user interface.
tool that can be used, however, receives no where near the same level of
support is the Security Forest Framework. At the time of writing
there are 11 pre-compiled exploits and these are very dated, the one
saving grace for this exploit engine is the fact it comes with hundreds
of un-compiled indexed exploits which may help you in your task.
There's also no reason why you shouldn't exploit a vulnerability the old
fashioned way - by hand ;-)