The subset of common syntax and behaviour is high enough to make it worth.
tcltest is available for both and runs from the same testfiles.
Conservative and sane programming leverages advantages of both environments
Rubbing Tcl, Jim and Tcllib against each other improves each of them: bugs and fallacies tend to show up.
Make ressource-consciousness accessible to the community.
I understand Tcl better now.
It scratches my itch.
I sleep better with less bits burnt on my hardware.