https://8th-dev.com/words.html

https://8th-dev.com/manual.html

Not sure if that is the best example, but go to the "network" section and you can see plenty of examples of connection stuff. Also cool things in the map, graph, console, hardware, DB (database), and nuklear (GUI) sections.

It is commercial though (albeit with a free tier iirc), so that may or may not be attractive for you if you wanted to see all source. For me, I just wanted to spend time playing around with a well polished ~forth that had all these things builtin, so fine for my more limited use cases. Coming from Python as my daily driver, I found it really easy to pickup the tooling and have fun building some super simple toy apps. The most default data structure is basically JSON, which is a pretty unconventional forth approach, but just clicked with me as I'm used to Python dictionaries. You might also be able to do all that with gForth, but not sure (referring to the ease of use from high level data structures).

There was also a forth-like language written in C# that was open source I think and pretty cool. It might have been retroforth which is available in various formats and has been talked about on here many times. I think the source comes with the zip file, but haven't looked in years. I assume it has some utility libraries for doing normal things.