Continuum is described as "a light-weight native OS X IDE for Mono".

It is hosted at http://code.google.com/p/continuum-ide/ as an open source project. Written by Jesse Jones.

There is no specific Cobra support at this point, but Continuum has a pluggable architecture and it's open source, so it should certainly be possible.

If launched from the command line, Continuum may say:
{{{
WARNING: The locate database (/var/db/locate.database) does not exist.
To create the database, run the following command:

  sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.locate.plist

Please be aware that the database can take some time to generate; once
the database has been created, this message will no longer appear.
}}}

You don't have to create the "locate" database, but Continuum's "open selection" won't be able to find files and right-clicking on types won't let you open the associated file.

See also: [wiki:IDESupport], EditorSupport