OpenOffice.org – Free Open Source Office Suite
OpenOffice.org is an office application suite for word processing, spreadsheets, presentations, graphics, databases and more. OpenOffice.org provides several localized version for almost all platforms.
OpenOffice normally known simply as OpenOffice, and it was originally derived from StarOffice from Sun Microsystems.
As the project aims says : “To create, as a community, the leading international office suite that will run on all major platforms and provide access to all functionality and data through open-component based APIs and an XML-based file format.” It can support most of the file formats found in MS Office, and some other applications.
Download:
Download page for all platform, Extensions.