OpenOffice.org is an Open Source, community-developed, multiplatform office-productivity suite. It includes the key desktop applications, such as a word processor, spreadsheet, presentation manager, and drawing program, with a user interface and feature set similar to other office suites.
Sophisticated and flexible, OpenOffice.org also works transparently with a variety of file formats, including Microsoft's.
Localizations of OpenOffice.org are available in 27 languages with more being constantly added by the community. OpenOffice.org runs stably and natively on Solaris, Linux (including PPC Linux), and Windows. Additional ports, such as for FreeBSD, IRIX, and Mac OS X, are in various stages of completion.
Written in C++ and with documented APIs licensed under the LGPL and SISSL Open Source licenses, OpenOffice.org allows any knowledgeable developer to benefit from the source. And, because the file format for OpenOffice.org is in XML, interoperability is easy, making future development and adoption more certain.
Homepage - http://www.openoffice.org/