But remember that Tcl was specifically designed for embedded scripting:

> In the fall of 1987, while on sabbatical at DEC's Western Research Laboratory, I got the idea of building an embeddable command language. The idea was to spend extra effort to create a good interpreted language, and furthermore to build it as a library package that could be reused in many different applications.

http://web.stanford.edu/~ouster/cgi-bin/tclHistory.php

If someone wants to use, say, LuaJIT to work on the $100k bounty for a 10x speedup of the Tcl language, they should go right ahead; prove that you can do it and claim the cash. (I guess I'll be rather involved in setting the test of the performance up; I've relevant experience.) However, that scale of acceleration is not trivial, not at all.

Off topic: It's refreshing to see this back and forth on HN without it being a sht slinging competition.

Tcl has a bigger footprint than Lua, but provides more services.