Z:gnu-www-ja-lessig-fsfs-intro--7aba41-The mechanism of this renderin/en

The mechanism of this rendering is an extraordinarily clever device called &ldquo;copyleft&rdquo; implemented through a license called GPL. Using the power of copyright law, &ldquo;free software&rdquo; not only assures that it remains open, and subject to change, but that other software that takes and uses &ldquo;free software&rdquo; (and that technically counts as a &ldquo;derivative work&rdquo;) must also itself be free. If you use and adapt a free software program, and then release that adapted version to the public, the released version must be as free as the version it was adapted from. It must, or the law of copyright will be violated.