The scripting language Tcl just turned 25; the five or six years centered on 1990 seem to have been the Baby Boom of such languages, for Perl is now 26, and Python must be over 20.
I learned Tcl mostly because of Expect. I haven't used that in years, but it was a very useful tool. Need to monitor a modem bank? No problem, we'll write a script. Need to copy gobs of files from scads of servers using FTP? No problem, we have Expect installed. Then there was/is Oratcl, and for a while I used the AOLServer web server, which used Tcl. Very occasionally I used Tcl/Tk,.
Those who set store by elegance in computer languages, notably Richard Stallman, complained about Tcl. Their complaints were not wrong, just not necessarily relevant to those who used the language. Heaven knows it had its quirks: everything a string, arithmetic requiring "expr", no complex types beyond lists and arrays, etc. etc. But I've used other languages that made me long for Tcl's "uplevel".
Anyway, Happy Birthday, Tcl, and Thank You, John Ousterhout.