I ran into a guy from high school and it turns out he worked for Microsoft back in the Windows Mobile days. He said that changing even a single button on a submenu would take six months of meetings, and if it involved other departments they would actively sabotage any progress due to the way MS internally made departments compete, so you could basically forget it. He said they literally backdoored software so they could sidestep other departments to get features in.
I think about that a lot.
Back in the day TCL was used in a few places in Pixar’s Renderman renderer (called PRMan), and in its connection to Maya. You could write little TCL scripts within the Renderman Artist Tools (RAT) that would be evaluated during scene export. I think this still exists in some form inside Tractor, which is their renderfarm management software.
It’s been a long time since I used prman but generally Python has replaced everything as the “glue” language, which honestly makes things a lot easier. VFX and game dev used to have a hundred different scripting languages rolling around.