Factor is a programming language designed and implemented by Slava Pestov (of jEdit fame). Some key features include:
- Postfix syntax
- Dynamic typing and scoping
- Syntactic support for lists, arrays and dictionaries (key<->value pairs)
- Full support for continuations (as in Scheme)
- Large math library
- Integrated web server that uses continuations to handle requests.
- and host of other features ...
The language resembles Forth a lot but also has features from Lisp. The latest version (0.69) also sports an optional JIT compiler for x86.
It sure looks interesting.