Adding more to the mix:
http://www.pcworld.com/article/3050320/software/microsoft-will-let-you-run-custom-apps-from-office-ribbons.html

Right now when I setup offices I install LibreOffice. I do so because it's free and does a very good job of being a complete replacement for MS Office. If the above pans out like I think it will I will have to change my thoughts.

Johnf