The RealNetworks Public Source License (RPSL) is a software licence. It has been approved as a free software licence by both Free Software Foundation and Open Source Initiative (OSI), but it is incompatible with the GPL and the Debian Free Software Guidelines. The RPSL is used by the Helix project. See also RealNetworks References External links RealNetworks Public Source License text Free and open-source software licenses Copyleft software licenses Public Source License