Booking.com is mostly Perl and doing gangbusters. Tcl is, for example, the lingua franca for F5 load balancers. I have more examples, but both are far from dead.
Tcl is a household name in the field of EDA tool scripting.
Virtually all software tools designed by Cadence, Synopsys, and Mentor include a Tcl REPL/console.
Any task performed in the GUI is actually executed in the REPL, making it easy to replicate a specific flow by just copy/pasting the commands displayed in the REPL into a Tcl script.
To load a script, you simply pass it as an argument when running the software.