[1] http://www.excelsior-usa.com/
Besides Excelsior, there are Aonix PERC, IBM J9, Codename One, JamaicaVM, RoboVM.
There are probably a few others.
Mark Reinhold mentioned on his "post Java 8" talk at Java One, that having an AOT compiler as part of the standard JDK is part of the wishlist.
[1] http://www.excelsior-usa.com/