phuse, I am currently working on a C2 plug-in that would support the ASP.NET SignalR library. SignalR support websocket but also long polling in case the user's browser does not support websocket.
The server backend would be all C# but the front end can support JavaScript (a Construct 2 plug-in).
So far, I have been able to connect to my SignalR server from C2. I am now looking into connecting into server functions and vice versa.
I will post a new plug-in thread as soon as I do have a working prototype.