Yaler - a simple, open and scalable relay infrastructure for the Web of Things (opens in new tab)

I bet that a commercial license would be available on reasonable terms: Oberon Microsystems have been around for quite a while, and are quite good people (I used their Blackbox [neé Oberon/F] IDE for personal stuff for quite a while, and it's one of the nicest development environments I've ever worked with. (It's a bit of a surprise to see them writing Java, though.)

True, but this seems great for a personal project/experiment.

Good catch, thank you for pointing that out.

Would also like to know. I think for commercial systems you would have to create a solution yourself, or else a commercially usable system like this would be well-known.