The
Open Content License (OPL) is a license designed for distribution of
open content material. This license is
not compatible with the
GFDL in that it does not allow the OPL licensed material, or derivation of such material to be sold; and restricts further versions to be licensed as OPL as well.
Projects using the OPL
External links
All Wikipedia text
is available under the
terms of the GNU Free Documentation License