From the Official Linden Blog:
"Stepping up the development of the Second Life Grid to everyone interested, I am proud to announce the availability of the Second Life client source code for you to download, inspect, compile, modify, and use within the guidelines of the GNU GPL version 2.
A lot of the Second Life development work currently in progress is focused on building the Second Life Grid — a vision of a globally interconnected grid with clients and servers published and managed by different groups. Expect many changes and updates in the coming months in support of this architecture. Much of the recent work has centered on securing the code against potential threats. More recently and still in development, we are moving more of the communications to reliable and cryptographically strong secure channels.
At Linden, we have always been strong advocates of the use of open standards and the advantages of using open source products. Though Second Life makes abundant use of non-standard technologies, our basic UDP protocol message system for example, we rely on open standards and open source implementations when appropriate and available. Since many of the components that will make up this network are not yet done, we are not publishing long white papers or RFCs at this time — instead, we are giving everyone what we have along with a goal of producing those open standards with the input and assistance of the community that has brought Second Life to where it is now.
Releasing the source now is our next invitation to the world to help build this global space for communication, business, and entertainment. We are eager to work with the community and businesses to further our vision of our space."
This is a bold and audacious move, and I applaud the Lindens integrity and foresight in making it. In the choice between changing the world and enriching themselves this feels like they've leaned toward the former, and I believe that deserves a lot of respect. I can't wait to get in there and play with it myself.