• Lotus Symphony

From author's site:

IBM® Lotus® Symphony™ is a richly-featured set of productivity tools that are intuitive and easy to use and provided at no charge.

Lotus Symphony puts you in charge – take control over spiraling upgrade costs, ensure access to documents well into the future with new standard file formats (ODF), get more from your current investments with support for Microsoft® Windows® and Office file types.... even extend your applications with the new Lotus Symphony developer toolkit.