Gen is a general utilities library for Tcl. Also, Gen is free (same license as Tcl itself). It is available on my personal site as well as on GitHub and Gitorious (see 03|Getting It).
The idea behind Gen is simple -- make 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.
Why? Because you are already trying to solve some other problems. For instance, let us say you want to write the contents of a variable to a file. You can look up the command syntax and get it done in several lines of code. It is not a question of what you are capable of but what is more convenient for you. In this case, it is more convenient to just call String2File. Because this is quicker, it helps you to keep your focus on your main problem and keep your flow going.
We hope you will find Gen to be a help with your work in Tcl!