Viral Contracts or Unenforceable Documents? Contractual Validity of Copyleft Licenses

This paper asks the question of whether copyleft free software licences constitute valid legal contracts, in particular with regards to the fact that it may create obligations through a distribution chain. There is increasing interest about the non-proprietary licence model expressed in popular documents such as the General Public Licence (GPL), but not enough work has been done in asking perhaps the most important question of all: are these contracts enforceable? Is there really a viral transmission of obligations? To do this the GPL licence will be analysed to try to determine whether or not the terms included are contractually valid.