Is the Second Life Viewer GPL-compatible?
Yes and no. The viewer is licensed under the GPLv2 with an additional FLOSS exception. This FLOSS exception allows linking to GPL-incompatible libraries. If you remove the GPL-incompatible libraries and strike the FLOSS exception from the license, then the client is fully GPL compatible, and may then be distributed with other GPLed works linked with it. Notable GPL-incompatible components: • Fmod (audio library) • Kakadu (JPEG2000 decoding library) • Apache Portable Runtime (compatible with GPLv3) Also see: FSF’s wiki on GPL compatible licenses.