What about WebSharper? It&#x27;s solid, open source (Apache 2.0) and they&#x27;re working on adding C# support for the next major version:<p><a href="http:&#x2F;&#x2F;www.websharper.com&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.websharper.com&#x2F;</a>