I have a feeling that server-side js will eventually become a major player in the web world, especially if solid, reliable implementations are created. The idea of having a uniform language to communicate between the server and client with a decent data transportation format (JSON) has been something I've long for, enough so that one of my New Year's resolutions was to start contributing to a SS-JS implementation this year.
I started Narwhal (a JavaScript standard library: http://narwhaljs.org) and Jack (a WSGI/Rack-like web server interface: http://jackjs.org) earlier this year with the intention of bringing JavaScript up to par with Ruby, Python, etc.
There are other nice SSJS products, but they're all very monolithic and self-contained (in a bad way). I'm hoping Narwhal will be more modular and open, like we have with most other languages.
I'm tracking your two projects on github and have also been watching ry's node project. I'm really interested in how SS-JS will develop. For one it necessarily removes the DOM model people are familiar with and it also has evolved in an environment that has fostered the growth of many interpreters without one being totally dominant. V8 and Rhino are both very manageable, it will be interesting to see how compatible they all remain and if one assumes the position as the de-facto standard.
I am really looking to use V8 more then anything. Rhino is nice but the momentum is with V8. The issue with those is that a feature is Java library support and I personally would prefer native libs then some hack to make Java libs work.
So one of the cool things about Narwhal is it was created with the goal of supporting multiple interpreters. Where possible, code is written in JavaScript to facilitate sharing between interpreters. For example, the "binary" module is currently about 700 lines of JavaScript, plus about 100 lines of C/C++ or JavaScript per platform.
While Rhino is currently the most complete Narwhal platform (mostly due to the ease of prototyping in it) We've also started working on V8 (github.com/tlrobinson/narwhal-v8/) and JavaScriptCore (github.com/tlrobinson/narwhal-jsc) support. They're still very incomplete but it's a start.
I asked a similar question some time ago - whether Javascript will become the long sought after unifying language of web development.
I was surprised that the other option seemed more appealing to people - writing interpreters/compiler in Javascript for other languages which can then run in the browser.
i'll be happier when john et al push through the next major lang revision
this clinginess to js strikes me of stockhold syndrome. people are working themselves into a lather as to how awesome and powerful it is, but most of this power is rooted in crappy hacks. namespaces for example. or crockfords currying stuff. very hacky.
js will do. it gets the job done. would i choose to code on the server side with it over python, perl, or haskell? nope
http://en.wikipedia.org/wiki/Server-side_JavaScript