You have experience with Tcl--certainly you're beyond the "When all you want is to run a Tk application" level. Someone hands you a .kit file; what do you do with it?
Experienced Tcl'ers know to run it against Tclkit, that is, invoke
tclkit some_application.kit
As Tclkit is an important idea, perhaps you'll want to learn it, or at least enough about it to download the executable [L1 ]
and launch the application that interests you. If not, perhaps you
can find someone with more experience to "unpack" some_application.kit for you and forward the *.tcl sources (and perhaps other texts and binaries) it packages. At this level, you see, Tclkit is a way to wrap up an application into a single file; it can equally easily be unwrapped into pieces that might be more comprehensible to a newcomer to Tclkit.