Keim has made a Flash port of Structure Synth. Not a lot of info here, but it seems that most of the EisenScript syntax has been implemented. Rules need to be programmatically created though, there is no free-text parser yet.
And if that wasn’t impressive enough, he also has created a version with Screen Space Ambient Occlusion. SSAO is a technique for creating real-time ambient occlusion simply by estimating the amount of oclusion by looking at the depth buffer. I’ve considered implementing it myself in Structure Synth, but had never thought that Flash would be fast enough to accomplish this.
And while I’m at it, Wonderfl is quite impressive in itself. It is a website, which makes it possible to edit and run small Flash programs, but most importantly it makes to easy to build upon other peoples work by forking it.
Art of Illusion
Example image by Jep (found at the Forum thread)