"Many wikis use the GNU Free Documentation License to protect their work. In fact, Memory Alpha's \"godparent\", Wikipedia, formerly used the GFDL. The GFDL is a copyleft license that is designed for the free distribution of software manuals and other similar documents."@en . . . "Memory Alpha:Why Memory Alpha doesn't use the GFDL"@en . "Many wikis use the GNU Free Documentation License to protect their work. In fact, Memory Alpha's \"godparent\", Wikipedia, formerly used the GFDL. The GFDL is a copyleft license that is designed for the free distribution of software manuals and other similar documents."@en . . .