Along with emacs, RMS originated the philosophy of FreeSoftware. He started the Free Software Foundation and the GNU Project (GNU's Not Unix) to build an entirely free operating system.
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He is also an activist, supporting various ideas -- not only FreeSoftware. His HomePage starts with a short intro and lots of action items:
It's not quite NetWar but he sure is politically active. For instance, as president of the FreeSoftwareFoundation, he has resorted to LegalThreats as well as advocating. For instance, take the case of StallmanVsFiddes. However, he should be remembered here mostly for his contributions to SoftSecurity via the IncompatibleTimesharingSystem.