Very Cool! I've got to try this out! I'm definitely picking up a bit of a Tcl vibe here, which is another language I've been wanting to try out. Especially with the integrated GUI toolkit, it's giving me some Tk vibes as well.

Does anyone know if there was any direct inspirational link from Tcl to Red/Rebol, or was it just by the nature of the idea of making an extensible langauge suitable for making lots of DSLs in?