Z:gnu-www-ja-microsoft-new-monopoly--9c201c-Some free software licenses, s/en

Some free software licenses, such as the most popular GNU General Public License (GNU GPL), forbid publication of a modified version if it isn't free software in the same way. (We call that the &ldquo;liberty or death&rdquo; clause, since it ensures the program will remain free or die.) To apply Microsoft's license to a program under the GNU GPL would violate the program's license; it would be illegal. Many other free software licenses permit nonfree modified versions. It wouldn't be illegal to modify such a program and publish the modified version under Microsoft's patent license. But that modified version, with its modified license, wouldn't be free software.