I've dabbled with Tcl since about 1988 starting on VMS when John Ousterhout's book was current. I now do a mix of application and system programming, mostly in C (with some scripting thrown in) with a focus on delivering financial information to institutional customers. I've slowly become functional with Oracle by "on the job training" since that is what we use.
My most-used Tcl extension is Expect by a wide margin. I can't begin to count the amount of time Expect has saved me.
My main past-time is astrophotography; you can see some of my work on my website, http://www.astrofoto.org/ . This picture is me setting up to photograph the 2001 Leonid meteor shower with my two boys (one 11 months, the other 3 years at the time of this photo) "helping" me.
(revived link to photo)