Pretty much every modern IDE with a plugin system could be repurposed into a message router, since they all have underlying code execution in their respective runtime environment (just as how in this case, Emacs was really just a Lisp runtime).
Certainly any of the major Java-based IDEs (Eclipse, IDEA, etc.) could host a message router, although this is quite boring as it's just Java. Amusingly though, Volkswagen's automotive dealership service tool, called ODIS, is built in Eclipse.
Certainly any of the major Java-based IDEs (Eclipse, IDEA, etc.) could host a message router, although this is quite boring as it's just Java. Amusingly though, Volkswagen's automotive dealership service tool, called ODIS, is built in Eclipse.
The Javascript IDEs like VSCode could as well.