TwinAphexも横暴ではあるが、reicastはGPLなんだから法的には問題無いのでは
https://github.com/reicast/reicast-emulator/blob/master/LICENSE

GPLと矛盾することを表記してるreicastもおかしいよ

>Rebranding/(hard)forks
>If you are interested into further porting/adapting/whatever, please do not fork off.
>We hate that. Really.
>
>Let's try to keep everything under a single project :)