The document provides an overview of free and open source software, focusing on Linux. It discusses the four freedoms of free software as defined by the Free Software Foundation. It describes some popular Linux distributions like ClearOS and BackTrack Linux. It highlights quotes from Richard Stallman about freedom and control. It also discusses the history of Linux from Linus Torvalds' 1991 post and the growth of Linux usage in various devices, servers, and supercomputers. In the end, it proposes a Per Scholas Linux supercomputer cluster project.