Minivmac 3.3.2 Alpha works well on the Raspberry Pi running Raspbian. You can download a pre-compiled ARM binary from this link:
You will need a vMac.ROM file (with that exact file name) which contains a Mac Plus rom. If you intend to do this legally, you technically need to own a Mac Plus, but that's another matter entirely.
I recommend reading up on this page for everything else you'll need:
One final note: sound appears to be buggy on the Pi for now. You can disable it with the "-alsadev noexist" option on the command line when starting MinivMac, or you can compile your own binary with sound turned off (plus, if you compile your own, you can set a custom resolution for MinivMac that will do real fullscreen, and a few other things)
Have fun, I know I am!