As someone who worked for a company for a few years on a vast Tcl codebase, a company in which almost every engineer lamented the fact that they were working in an unused and unknown language, it warms my heart to see that it was used for this.
http://antirez.com/articoli/tclmisunderstood.html
I dabbled with it myself, writing a simple TCL interpreter in C, but I always find myself comparing it to FORTH a language I still find it easy to love.