Kudos to Sun for beginning to fight the scourge of license proliferation. Effective immediately, Sun is retiring the Sun Industry Standards Source License (SISSL) under which OpenOffice has previously been published. According to Louis Suarez-Potts,
How does this move affect OpenOffice.org? As most know, OpenOffice.org code was launched under the dual banner of the SISSL and LGPL; licensees could choose which one they wanted to use, and nearly all have chosen the LGPL. Effective with the announcement that Sun is retiring the SISSL, however, OpenOffice.org will in the future only be licensed under the LGPL.
For users, the simplification means: no change. OpenOffice.org remains free to use, distribute, even sell. One can freely use it in commercial as well as government environments; nothing has changed.
For vendors, distributors, add-on and plug-in writers of OpenOffice.org: The LGPL allows for commercial distribution without affecting derived products in the same way as the GPL.
For developers and other contributors: As the code will be licensed only under the LGPL, modifications to the source must be published. (The SISSL did not require all changes to the source to be published.) As most OpenOffice.org contributors are already openly contributing to the community, we anticipate no problems. And for those who have been using the SISSL exclusively, we invite you to join us.