[ephaeton]

Yes. I've written a test framework for another software I'm developing that (optionally) sets up an environment for the executable under test, (optionally) launches and monitors the executable (process state, stderr/stdout), connects to the process via a WebSocket (that's what that executable does) and then tests the surface of the exposed WS-API. As the executable runs under windows & linux, embedded and not, this approach lets me run the test suite under all different hosts and connect to localhost or the thing running elsewhere. So, in my case, you may not see it in a product; but the product we're building is continuously tested with a myriad of racket programs.