What is the main difference among Reicast, Flycast and BeetleDC?

Previously I can download Reicast Core in PC RetroArch. But now I can only find Flycast Core instead. In Android I can get Reicast, Flycast and BeetleDC. Is there any obvious difference among these cores?

I have tried Reicast and Flycast cores on Android. Seems there is no big difference between them. KOFXI and KOFNW in bin/lst format still can not be played in Android. BeetleDC is missing its Core Info, so I cannot test it right now.

There is no difference, the core simply got renamed after upstream requested it, flycast is the new and definitive name (Beetle DC was a temporary name). I guess we need to cleanup the cores with the old names.