This article discusses the possibility that, if an OS solution or platform has considerable market power or is a de facto standard in a relevant market, the OS licence's terms (requiring redistribution free of charge) and/or the GPL's Copyleft provisions might be found to be exclusionary or unfair to a non-OS operator who is an intellectual property (IP) right holder. The article focuses specifically on the arguments surrounding unfair and/or exclusionary terms of access to a market, by looking at the way in which this issue has previously been assessed in the context of standard setting.