There has been a flurry of activity on Twitter after Rich Hickey’s recent announcement of ClojureScript. Clojure was initially developed for the Java Virtual Machine, and although there has been a project to port it to the Microsoft CLR (with only limited success), this development looks like it will radically extend the usefulness of the language. ClojureScript is a subset of Clojure, and I assume they’ll take the opportunity to get rid of parts of the language that aren’t really used in production applications. For example, use of eval is typically frowned upon by Lisp developers.
For me, the highlights are that the ClojureScript compiler is written in Clojure. The standard Clojure implementation has a compiler written in Java and a library that is written mainly in Clojure requiring work in two languages to extend it. Writing the compiler in the language itself means that improvements in the language can lead to improvements to the compiler too.