Kendo UI - a framework for modern HTML UI
I apologize in advance if this opinion offends anyone, but every HTML UI kit that I've seen simply can't hold a candle to  native kits such as WinForms, WPF or even Cocoa. I would really love a write-once browser based solution, but I just can't see that type of solution ever catching up to native tech.How long do we have to wait before the browser can catch up? Do you think it will ever happen?The closest thing that I've ever seen is Silverlight. With it I've been able to make some very excellent front-ends, with EASE, that look and behave identically between Mac and Windows. EDIT: The only challenge with Silverlight has been wheel-scrolling, which works fine on Windows but only works in Out-Of-Browser on the Mac.