This is similar to the lang-tcl.js in JavaScript Prettify.
All comments are adapted from the JavaScript Prettify.
To use, include prettify.js and this file in your HTML page.
Then put your code in an HTML tag like
proc foo {} {puts bar}
I copy-pasted lang-lisp.js, so this is probably not 100% accurate.
I used http://wiki.tcl.tk/1019 for the keywords, but tried to only
include as keywords that had more impact on the program flow
rather than providing convenience. For example, I included 'if'
since that provides branching, but left off 'open' since that is more
like a proc. Add more if it makes sense.