In reply to Jan Dembowski.

This sounds like the stupid arguments from the past where people talked about the "spirit of the GPL" to prevent people of forking etc. Eithers its ok according to trademark law to do as Yablon or its not. Thats the basic question and the only question of any relevance. Nothing concerning him as a person, quality of the work, or anything else regarding anything else but that basic question is of any interest. He could be the friendliest o thef friendliest and a completly moral outstanding citizen or a complete and utter ahole it would still not have any bearing on the legalities.