Open Publication License
While the Open Publication License replaced the Open Content License, the two licenses differ substantially. The Open Publication License is not a share-alike license while the Open Content License is and the Open Publication License can optionally restrict the distribution of derivative works or to restrict the commercial distribution of paper copies of the work or derivatives of the work, whereas the Open Content License forbade copying for profit altogether.
According to the Free Software Foundation, the Open Publication License "can be used as a free documentation license" and is "a copyleft free documentation license provided the copyright holder does not exercise any of the 'LICENSE OPTIONS' listed in Section VI of the license." It is not, however, compatible with the GNU FDL.
- Open Publication License text dated June 8, 1999.