OpenOffice.org is the open source project through which Sun Microsystems is releasing the technology for the popular StarOffice productivity suite.
It is an 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 establishes the necessary facilities to make this open source technology available to the developer community.
OpenOffice.org is a free, Open Source alternative to MS Office with a Word compatible word processor, a complete Excel compatible spread sheet program and a Power Point like presentation software and drawing program and also allows to save to PDF file.
In addition, OpenOffice.org offers enhanced printing capabilities and options for direct connection with external email programs as well as form-letter management to send letters to addresses from a database.
Download it here.