Note from the author: This license is obsolete. It has been superseded by the OGL as published by Grey Ghost Games.
From Wikipedia:
The Fudge role-playing game system was created in 1992 by Steffan O'Sullivan with extensive help from the rec.games.design community. The name stood for "Freeform Universal Donated Game Engine" until Steffan O'Sullivan changed 'donated' to 'DIY' in 1995.
One reason why Fudge succeeded is that the author released it under the "FUDGE Legal Notice", a license that removed most restrictions on non-commercial use. However the FUDGE Legal Notice (more commonly known as simply "the Fudge license") was never intended to cover any work other than its eponymous role-playing game. Derivative works which were to be distributed for a fee required written permission from Fudge's author, Steffan O'Sullivan. The details of the Fudge Legal Notice were modified and expanded from time to time as O'Sullivan updated his work, but the essential elements of the license remained unchanged. The 1993 FUDGE Legal Notice allowed reprinting of the Fudge rules, including in otherwise commercial works, as long as certain conditions were met. The 1995 FUDGE Legal Notice permitted the creation of derivative works for personal use and for publication in periodicals.
In March 2004, Grey Ghost Press, Inc. acquired the copyright of Fudge, and on April 6, 2005, they released a version of Fudge under the Open Game License 1.0a, making it open for commercial use.