Open Office

Open Office is a free open-source alternative to Microsoft Word, PowerPoint and Excel. I've used it, and it's not bad. I agree with this guy on Microsoft's products:
But the one biggest kudo I have for Open Office is that it doesn't try to help me or automatically format a document I'm working on when I don't want it to. That is one of Microsoft Office's biggest annoyances, that it “knows better” what I want to do than I do. I've lost count of how many times I've had to undo something MS Office insisted I wanted to do even though I had no intention of doing what MS Office did for me.

Man, is that annoying, and it happens all the time. Unfortunately, I can't recommend Open Office, based on my experience. Perhaps it's better than when I used it, but there was a problem with compatability with the Microsoft Versions. Someone sends you a document he made with Word, and when you try to edit it and send it back, something fails. Probably he has used some feature not fully supported by Open Office. In any case, it is too much of a pain to work with if you are doing work with other folks who use Microsoft products.