I've such fond memories of Ruby. Just moved to Kotlin since and it feels like a Ruby-with-types-and-Java-interop. Both Ruby and Kotlin are OO-first but FP-ready. Both are very expressive.

Interesting enough the JVM is so much further ahead that my HTTP-server is implemented "in JVM" (the built in "Sun" HTTP server is good enough for production use in our case). Where as in Ruby land there was (and is) always a native HTTP-server in the dependencies of a production app.

JRuby is another option for Java interop, although inline types are sorely missed still. TRuby is an interesting project in that regard though