several vaguely related projects worked on by me: a 3d engine with a javascript-like scripting language (pdsys); an older scheme dialect (vmsys); ... (2009-04-28: I have been gone for years, may try to put up some newer stuff...).
Snack combines a high-level object oriented language (think JavaScript) with a bytecode execution engine. An example air traffic control game (a port of the classic ATC) and a text adventure framework are included.
Try Scheme is a Scheme interpreter that runs in your web browser. No installation. Just click and go. Full support for continuations and syntax-rules macros!
Smith is an open source, cross-platform ColdFusion® engine, written entirely in Java. Running on top of Java Runtime Environment and Java Servlet Container, it can be deployed virtually on any operating system and work with any web server.
SuperClass is a JavaScript pre-processor/interpreter object, designed
to facilitate class-based OOP in JavaScript. NOTE: Project is closed. Replaced by: http://sourceforge.net/projects/jsclass
NJS is an independent implementation of the JavaScript language developed by Netscape and standardized by ECMA. It is designed to be re-entrant, extendible, fast, and programmable.