Undertow now supports HTTP2 Draft 15
So far, we have verified HTTP/2 interop with the following browsers:
Chrome Canary (41.0.2217.0)
Firefox (Nightly build of 36.01a)
Internet Explorer (Windows 10 Preview)
The demo site contains instructions for testing it out, including getting it running locally. The HTTP2 code is still quite new, and will be evolving a lot over the coming months. For now most features of HTTP2 are supported, with the exception of priority, which is ignored.