This document introduces OpenSolaris, a open source version of the Solaris operating system. It summarizes the history and key features of OpenSolaris like ZFS for storage, DTrace for system monitoring. It also describes how to install OpenSolaris and get support. The future Project Indiana distribution is mentioned, which aims to make OpenSolaris easier to use and customize. Reasons given to use OpenSolaris include its technologies, free and open source nature, and career opportunities from learning its skills.