@perloid I have used tcl a bit when playing with expect and sqlite, but I think I learned it when messing with the SunOS package system back in uni.
It's an oldie but goldie and I'd like to do more with it at some point, not the least to look into [incr tcl].
I find it fascinating how Tcl manages to do several things opposite from common wisdom (dynamic scope, references by name only, are the two main ones) yet somehow ends up with equivalent power to more abstract languages like Scheme. #picolisp is rather tcl-like in that aspect and intrigues me too.