A quick follow-up to my earlier post.
I’ve just committed a very minimal starting point for Macaque: an ECMAscript-based language built atop SpiderMonkey. My intention is to structure things similarly to PHP: a core (which in this instance will be a small wrapper around SpiderMonkey, along with bundled classes and functions), optional extension modules, and all hanging together from one of a number of SAPIs. Write now there’s a very very minimal CLI SAPI, although its code shouldn’t be relied upon for anything as I haven’t defined how the server interface will actually work yet. There are also only two built-in functions (beyond those provided by SpiderMonkey itself): dprint and dprint_r, both of which do the same thing (they dump whatever arguments will be passed to them via fputs). In PHP, these two functions are provided by the Eregansu Core.
Anyway, if you’re curious, have a look through the SVN repository at Google Code.