John Buckman makes espresso machines at Decent Espresso which are controlled by an App on an Android tablet which is written in Tcl (via Androwish). Here's a presentation at EuroTcl 2019 about it: Video: Coffee without Java
John founded and ran Lyris [L1 ] in 1994, ran it for 11 years, and wrote their ListManager and MailShield products, both of which use tclhttpd as the web server platform and engine. At Lyris, he hired David Gravereaux to write a "socket" command replacement optimized for Windows' async tcpip calls, which David then made open source, which gives amazing speed gains. John sold Lyris in April of 2005.
John currently uses Tcl extensively behind the scenes at Magnatune [L2 ], an online record label he runs, and BookMooch [L3 ] is an all-Tcl-all-AOLServer used book exchange community he now runs. You can email John : https://magnatune.com/info/email_us?to=john