This blog entry is a repost of an answer I wrote at programmers.stackexchange.com.

SignalR has a JavaScript API. SignalR helps build asynchronous scalable web applications with real-time persistent long-running connections. Scott Hanselman wrote a great blog post about this.

If that’s not your speed, you may be looking for something more like WCF Support for jQuery, which seems to have sprung up from the old WCF-RIA jQuery client. Looks like this will be part of ASP.NET MVC 4. Thewiki page for this project seems to indicate that its flexible enough to plug in to WebSockets.

I’m a little concerned about WebSockets in the near term. There are some questions about just how Internet infrastructure (particularly in corporate environments where proxy servers are common) will handle WebSockets. I believe SignalR has strategies to help mitigate this by negotiating fallbacks when WebSockets don’t work. Scott Hanselman has another blog post about this which makes some good points in this direction.