Say you are in the middle of solving one problem and find you need to solve another. Suppose you need to insert into a string. You could write code that will do this, but it would be nice and convenient if there were something that does it all for you with one command.
Gen is about making it a little bit easier to write Tcl programs. Gen is supposed to be code that you could well write yourself but do not want to have to.
In case you do not know (or remember) how to install a Tcl library, we have also made a screencast that shows you how to get things up-and-running within minutes. Give it a try.