Eh, having used both Tcl and Lua, I definitely think Lua is the better of the two when it comes to a scripting engine for games.

And I think Lua is more elegant than TCL overall. TCL's stringiness really gets clumsy in certain types of programs, and it's a much larger target than Lua overall.

Not to say that TCL is bad, but I'm glad that dict-based languages prevailed over TCL's string-based-ness