Apache OpenOffice - The Free and Open Productivity Suite
is a Free (as in free speech) office suite and an Apache Top Level Project.
Apache OpenOffice - formerly wellknown as OpenOffice.org - is the leading Free 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 the data in an international open standard format and can also read and write files from other common office software packages.
Apache OpenOffice is the result of over twenty years' software engineering. It has been downloaded over 100,000,000 times.
It's a product developed by a large (and really great) international community. The project involves a large range of different skills, levels of involvement and degrees of technical expertise. People from all over the world are working together to improve this office suite.