Yup. The prime caveat is that any gems that use C extensions have to be replaced with Java equivalents (mysql2, for example), but it runs just dandy. The boot

Yup. The prime caveat is that any gems that use C extensions have to be replaced with Java equivalents (mysql2, for example), but it runs just dandy. The boot time is atrocious, but you can run your Rails app multi-threaded in a single process, and once the JIT warms up, it's pretty danged speedy.