opensim-SC is a fork of OpenSim, and OpenSim is a clean room fork of Second Life. They are all 3D virtual worlds that are open, users can create their own content, these are not games. Second Life is a proprietary server, with open source viewer. OpenSim is an open source server that works with Second Life viewers. See doc/index.html for details. INSTALL.md for installation instructions. Differences.txt for the differences between OpenSim and opensim-SC. coderDocs/ for the coder level documentation.