http://www.libreoffice.org/

Libre Office is an open source cross platform office suite.

Libre Office is a fork of the Open Office project. If you haven't tried Libre Office or Open Office in a while you should really give this a try. The quality and compatibility with Microsoft Office has improved a lot in the past couple years.

• All the typical office suite applications, Word Processor, Spreadsheet, Presentations, Drawing, Database
• Compatible with the latest Microsoft Office file formats.