RACJ and all others without word.
open source software so it's free and has all the main products of office(word, excel, powerpoint, etc...) I use it at work and home on my linux and windows box. There is also a portable version that can be placed on a USB key(flash drive, thumb drive, pickle, etc..) and can be used in any computer that recognizes the USB key.
A great piece of software that can even convert the files to PDF for those on here that love adobe.
Provided tools and how they map to office:
Writer = Word
Impress = Powerpoint
Calc = Excel
Math = similar to Matlab or Methmatica or some unknown to me office tool
Base = Access
Draw = Visio