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...).
The Pixel Art Construction Kit is a tool that allows people to easily build isometric stuff, manipulating their little cubes as Lego(TM) blocks.
The tool is made by a lightweight core and some plugins that provide (hopefully) all the needed functions