Viral Contracts or Unenforceable Documents? Contractual Validity of Copyleft Licences

This article attempts to ask the question of whether copyleft free software licences constitute valid legal contracts, in particular with regard to the fact that they may create obligations through a distribution chain. There is increasing interest in 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.