Mmmm, LaTeX...
Never mind your OOXML vs ODF - the future is plain text!
With Texlipse and MacTex I can use Eclipse for most of my document creation and editing now and Office 2008 is installed just because a) it's covered under a MS Campus licence anyway and b) some people insist on still using proprietary formats to send me stuff. Add in version control using Eclipse Team Providers for Subversion (or your preferred repo) and you've got a much better and more compatible collaborative working solution than Office and Sharepoint for a lot less cash (and also working properly, now).


