There is an open source software package at OpenOffice.org that's pretty interesting. I just started using it last week. It has not only the standard stuff that makes up Microsoft office, but other cool stuff like "Math" which is a program that makes mathematical expressions like complex fractions and integral signs, etc.
One of my favorite parts is the .pdf writer. It is so easy to use (just click one button and save the file). The .pdf writer is incorporated into the word processor, the spreadsheet, the database, the slideshow program, and the math program (AWESOME).
Additionally, when stuff is giving you hellacious formatting problems in Microsoft Word, it usually cooperates in Writer.
I've already given this program to a couple other people and I haven't heard any negative feedback yet.