This is a parser, processor and visualiser for CGA Shape Grammars. It currently only implements a very small subset, and is certainly very buggy. It is only really tested in Chrome.
Rotate the 3d view with left-mouse button, pan with the right, zoom with the scroll wheel. Type in the box, see changes in the 3d view. Chose the things from the drop-down menus.
You grammar will be saved in localStorage, so you can come back later!
Go look at the complete CGA reference.
Grab the source from GitHub.
s, t, r
[ .. ]
envelope, offset, setback, ...
Have fun! If you make anything cool I'd love for you to tell me on twitter: @gromgull