Yes, you’re right. JEmu2 itself is legal… until someone starts a game.
Although that depends as well; some of the (non-arcade) games are actually put in public domain.
Have you got on to Elias yet about the broken input handling on Linux?
Cas 
Actually both Mac and Linux have problems now (Mac even more so than Linux), and at least on Windows vsync seems broken (in combination with some video cards).
I’ll have to provide test cases, but lately I have so little time… :-[
I suspect it’s my own silly mistake, and actually I wonder why keyboard input works at all on windows at the moment :-[
I’ll update tonight and see how it fares on Linux/Mac
I think this is currently seriously damaging jemu2’s prospects. I can’t send it to anyone or recommend it when even I can’t work out how the heck to play even one single game - and I’ve previously used it a lot (but not for 6 months).
Seriously, having no help, no instructions, no way to do anything except run games that you then can’t play … it really isn’t a good idea.
The keys are explained in the help menu, and on the page you started JEmu2 from, and you can use the keyboard configuration screen to work out which keys are used.
But the real problem now is, the current version is broken on Linux and Mac (keyboard isn’t working at all), and after the server had been recently hacked and secured again, I didn’t yet receive my new login to upload the (hopefully) fixed version 
Nonetheless, I agree that it would be even nicer to have a little screen before starting each game that mentions the controls, but I never got any complaints about that until I accidently broke the latest version (has something to do with the new networking code).
If all went well with the new server, the fixed version should be online now (version 4.1.2, see the GUI title).
Could people with an (Intel) Mac or Linux give it another try and see if the controls work now?
Still not working here on my intel macbook :s
Although the demo’s of the arcade games are fun to watch, I would like to play 
Oh, crap
But thanks for testing!
Maybe I’ll have to revert back to an old LWJGL until I figured out what’s going on. At least JEmu2 used to work reliably on Windows, Linux and OSX/PPC, and by reverting back LWJGL I could rule out the possibility if LWJGL’s behaviour with keyboard input really changed and broke JEmu2.