The Free Software Movement is an extension of what remained of hacker culture after it collapsted in the early 1980s. The Free Software movement is supported by the Free Software Foundation. The main Free Software project today is the GNU Operating System.
The Free Software Movement is a mainly political movement where Freedom is highly valued. Compare this to Open Source where the politics are left out and only the superiority of the development model is considered. Many Free Software advocates see this as dangerous because the Free Software development model is not always the most efficient. However, the freedom to modify and share software is more important to members of the Free Software Movement than the efficiency of the development model.