As the OpenOffice.org 3 website notes:
OpenOffice.org 3 is the leading open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It is available in many languages and works on all common computers. It stores all your data in an international open standard format and can also read and write files from other common office software packages. It can be downloaded and used completely free of charge for any purpose.
OpenOffice.org 3 is the result of over twenty years’ software engineering. Designed from the start as a single piece of software, it has a consistency other products cannot match. A completely open development process means that anyone can report bugs, request new features, or enhance the software. The result: OpenOffice.org 3 does everything you want your office software to do, the way you want it to.
Easy to use
OpenOffice.org 3 is easy to learn, and if you’re already using another office software package, you’ll take to OpenOffice.org 3 straight away. Our world-wide native-language community means that OpenOffice.org 3 is probably available and supported in your own language. And if you already have files from another office package – OpenOffice.org 3 will probably read them with no difficulty.
and it’s free
Best of all, OpenOffice.org 3 can be downloaded and used entirely free of any licence fees. OpenOffice.org 3 is released under the LGPL licence. This means you may use it for any purpose – domestic, commercial, educational, public administration. You may install it on as many computers as you like. You may make copies and give them away to family, friends, students, employees – anyone you like.