OpenOffice.org is a complete office suite, available on many plateforms such as Windows, Linux, mac OSX, Solaris that offers :

• a word processor Writer
• a spreadsheet Calc
• a presentation software Impress
• a vectorial drawing software Draw
• an equation editor Math
• un new data base module Base

OOo, its short name, has a lot of advantages comparing to its competitor. Here is a non exhaustive list.

• Free software : OOo is under LGPL license that implies that you can legally: use it, redistribute it, deploy it in your company ;
• Technically validated : the file format is XML (contained in a Zip file). It ensures then the maximum of interoperability between softwares. Its structure has been the base of OASIS consortium work defining a standard of office suite file format. This format will become even an ISO norm during the year 2005 ;
• Perrenity : the internal structure of document, like the sources program itself, are accessible, documented and freely useable.

If you are interrested in more informations, you can browse the official website fr.openoffice.org (and read the links sections).