>>8
Just like cdr is your other car, Tcl is your other Lisp. The other homoiconic language (are there any more apart from Tcl and the Lisp family?). Instead of being based on lists, Tcl based on strings, which makes it slow, but not as slow as Ruby with MRI, and you're not going VROOM VROOOM with Tcl anyways. Other than that, the spirit is similar to Lisp in several ways, and the language is clean and simple. And uplevel is a nice way to implement things you'd use more complex macros for in Lisp.
My only gripe with Tcl is its scoping (sucks) and the way variables work (like a shell).