Linden Lab, creator of the "Second Life" online virtual world, is open-sourcing the code of the sites viewer application, enabling developers to make modifications, enhancements or add new features to the Second Life Viewer.
The third-party support libraries and open-source code are available for Windows, Linux, and Mac OS X.
The Second Life Viewer is used by subscribers (aka "Residents") to access the virtual worlds "Grid." Freely-downloadable from the Second Life Web site, the Viewer software enables Residents to control their in-world avatars, interact with each other via IM (instant message), create content, buy and sell objects, access multimedia content, and navigate around the virtual environment.
Linden Lab has released the Viewer source code under the GNU GPLv2 (General Public License, version 2), as well as under a separate license for entities that wish to reserve the ability to create proprietary extensions for the viewer.
Currently, due to third-party licensing restrictions, some proprietary components are still necessary for an optimal experience, according to the company.