Office compatible suites that are open source. If you like them then donate to allow the developers to continue to give us free stuff that works...
Open Office in conjunction with Apache, one of the primier web servers in the world, bring you an Office Suite that will open and allow editing of the more recent Microsoft Office documents.
Libre Office is another free office suite comparable to Open Office and compatible with much of the latest Microsoft Office. You can try either Open Office or Libre Office and see which one you prefer. Please, if you feel that it accomplishes what you want, donate to they can further improve the software.