Over on tirania.org is a article on OpenOffice-based applications with Mono and MonoDevelop:
A couple of years ago, Michael Meeks and the OpenOffice community ported the bridge to work with Mono which allows developers to create OpenOffice based solutions using any of the Mono programming languages (C#, Boo, IronPython, IronRuby, F#, VB, Nemerle and so on).
But even if the engine existed, it was not properly installed in the system and getting a C#-based OpenOffice solution required lots of Unix skills, the kind of skills that would likely be in short supply by those that interested in OpenOffice automation. We fixed this in this last development cycle, so now a Novell OpenOffice installation will have everything you need.
Michael Hutchinson, one of our MonoDevelop hackers has put together the missing pieces to simplify the process. He has created the solution templates necessary to create these solutions, and packaged them as a Mono.Addin for exiting MonoDevelop users.
Despite some issues with the exposed API (described in the article) this is pretty exciting stuff. In conjunction with the possibility of writing Evolution plugins using Mono we are closer to having a fully-managed desktop environment with an integrated [or integratable] suite of first-class tools. I'm very much looking forward to the next release of MonoDevelop and hoping some of this stuff gets included.