OpenOffice 2 is the latest incarnation of Sun's OpenOffice -
http://www.openoffice.org/
It's a fullblown office suite that is 99.9 compatible with Microsoft's overpriced (and buggy) stuff - the only places that it may stumble a bit is opening very complex interlaced Word or Excel documents (which very few people create anyway). Reads and writes lots of formats including the MS ones.
Available for Windows, Linux, Solaris, BSD and Mac - so you can have a common Office Suite in a mixed environment.
To be honest I think that it's now better than MSOffice in many ways. I hardly ever use MSOffice anymore.
And it's completely free, no strings.
Join the wave of the OpenDocument future!
PS: MS's "Works" was/is an awful, incompatible, very limited and buggy abortion that Gates should be ashamed of having produced (if he hed any shame). It was _just_ enough to get you hooked and so bad that you ended up going out and spending lots of dosh on the full Office (which was what was intended).