I think by any reasonable interpretation of the GPL, they are still breaking it by using a wrapper around the binary. Why? Well... well, the GPLv2 does apply to them. There's no question about that by distributing Dosbox with or without source modifications, they have accepted the licence (see …

thought I should jump in at this point and mention that id software have released the source code to their old games (Up to and including Quake 3 as the most recent I believe) into the public domain. It's worth mentioning that they're not in the public domain, but they are licensed under the GPL v2 …