Controversial free software advocate Richard Stallman, founder of the Free Software Foundation and the GNU project, will speak at the University of Minnesota at 6:30 p.m., Tuesday, Oct. 21 in Rm. 175, Willey Hall, 225 19th Ave. S., Minneapolis. The event is free and open to the public. Stallman pioneered the concept of "copyleft", the practice of using copyright law to remove restrictions on distributing copies and modified versions of a work for others and requiring that the same freedoms be preserved in modified versions. Stallman is the main author of the most widely used free software license, the GNU General Public License. Microsoft chairman Bill Gates and CEO Steve Ballmer have publicly criticized the GNU General Public License and some software companies have likened it to a virus that will "destroy the software industry". In Stallman's talk, "The Free Software Movement and the GNU/Linux Operating System", he will discuss the Free Software Movement, which campaigns for the freedom of computer users to cooperate and control their own computing activities. Stallman's lecture is sponsored by the University of Minnesota's Software Engineering Center. For more information, visit http://www.msse.umn.edu/stallman.