I don't know Dylan, but compiling Ruby is a nightmare. As such it's also a fun challenge (working on "as static as possible" Ruby compiler).

Actually, compiling Ruby is not that bad, horrible grammar (from the perspective of having to write a parser - as a user o the language I like it) notwithstanding.

Compiling Ruby into efficient code is a nightmare.

The problem is largely that there's a total lack of delineation of application read/load time and runtime, coupled with the ease of being able to mutate the object model.

E.g. in theory on return from any method statement the entire world might have been transformed. 2 + 2 = 4 one moment, only for 2 + 2 to have side effects and return 5 the next...

The "quick and dirty" way of compiling Ruby is to accept that you'll need expensive dynamic message call invocations all over the place.

Optimizing beyond that is a lot of work to ensure you can handle it when people start playing silly games. The jRuby Truffle backend is probably the best bet at the moment (Chris Seaton who did the initial work on that is on HN). If I ever get that far with mine, I'll be stealing lots of ideas fro there...

Dylan is a Lisp with Algol like syntax targeted for systems programming with a REPL, AOT compiler and IDE like environment.

So what you are telling about Ruby is also an issue in Dylan, given its Lisp heritage and flexibility.