Show HN: Detect software running from JavaScript in a browser

The demo currently only looks for these services but in theory could detect anything that opens a listener on a fixed port number: MySQL, Redis, ElasticSearch, MongoDB, Dropbox, Steam, DAAP media players, and Tor (daemon, browser, or Brave Tor mode).

I've been trying to accumulate a list of some of the more popular services that can be discovered this way here: https://github.com/wybiral/localtoast/blob/master/js/index.j...

It works in Chrome, Firefox, and curiously enough even the Tor mode of Brave Browser. Safari doesn't seem to allow these types of requests.

You could also check for the LAN IP with WebRTC and scan (at least that network as a /24) for services. You'd probably want to do something like that in a worker. Besides that, obviously browsers should seek permission for web sites to access resources from loopback/RFC1918/RC4193 addresses. You will however usually not be able to get information from them (CORS) but might affect services (get a ROKU to open an app etc.) with GET/POSTS to certain services or devices.

User configuration options would help, so that in the browser you can specifically configure what connections are permitted.