It compiles a major subset of Apple's Dylan (http://lispm.dyndns.org/documentation/prefix-dylan/book.anno...) to JavaScript, both for use on a CommonJS implementation and in the browser. A bootstrapping compiler is implemented in JS, but the same compiler is also available in Ralph itself and features define-macro (Cl-like). The whole runtime is defined in Ralph as well and provides a single-inheritance object system (including next-method): https://github.com/turbolent/ralph/blob/master/src/runtime/c...
I notice that it doesn't support multiple inheritance or multimethods; out of curiosity, is that because of a principled objection to them, or more because it wouldn't be convenient to implement them?
At the beginning I tried implementing various object systems. The first one was indeed multiple inheritance with multimethods, based on C3 linearization
(http://en.wikipedia.org/wiki/C3_linearization) and didn't use the prototype chain, but wasn't finished. The second one was similar to Clojure's protocols (define-protocol, extend-protocol, ...), but wasn't very handy.
The current one is single-inheritance, because it uses the prototype chain. It's a compromise between speed and usefulness. I'd prefer having multimethods (and maybe also multiple inheritance), but speed is a bit more important, as JavaScript is already quite slow.
So far I'm quite pleased with the single-inheritance and single dispatch solution, which basically works like that: https://gist.github.com/866506
It compiles a major subset of Apple's Dylan (http://lispm.dyndns.org/documentation/prefix-dylan/book.anno...) to JavaScript, both for use on a CommonJS implementation and in the browser. A bootstrapping compiler is implemented in JS, but the same compiler is also available in Ralph itself and features define-macro (Cl-like). The whole runtime is defined in Ralph as well and provides a single-inheritance object system (including next-method): https://github.com/turbolent/ralph/blob/master/src/runtime/c...
Almost all of the features are shown in https://github.com/turbolent/ralph/blob/master/src/tests/run... and I'm using it a project now. To build HTML5 apps, there's a small toolbox: https://github.com/turbolent/toolbox
Maybe it's useful to someone else. Cheers