http://board.flatassembler.net/topic.php?t=22194
(MenuetOS is Ville's project)
The code was GPL, but kolibri did replace copyright headers and that was Ville's main gripe. Whether or not that breaks the GPL, I cannot say (they kept his name in the license file).
To me, as an outsider to these projects, making the 32-bit version open source and the 64-bit version proprietary feels hostile.
How many years should pass until it doesn't matter if a fork was "hostile" or not and only open source software remains?
But that isn't all that took place; please read the linked post.
I think the author's wishes should be respected above all. Don't you?