In case you clicked on this link instead of this one, WLUG will be co-sponsoring some talks on this subject.
OpenOffice is the commonly used name for OpenOffice.org, a free office suite based on SunMicrosystems's StarOffice but released under the LGPL. The FAQ explains:
The trademark for "OpenOffice" belongs to someone else. Therefore we must use "OpenOffice.org" when referring to this OpenSource project and its software.
See OpenOffice.org for more.
33 pages link to OpenOffice: