...a next generation WPF?
As everyone who's involved in client-side .NET development knows, the past half decade have been a very sad time. Where WPF started off as a game-changer, it now seems to have been all but forgotten. WinRT came along and took many of the lessons of WPF but it's currently not usable on the desktop.
After a few months of trying to reverse-engineer WPF with the Avalonia Project I began to come to the same conclusion that I imagine Microsoft came to internally: for all its groundbreaking-ness at the time, WPF at its core is a dated mess, written for .NET 1 and barely updated to even bring it up-to-date with .NET 2 features such as generics.
So I began to think: what if we were to start anew with modern C# features such as (gasp) Generics, Observables, async, etc etc. The result of that thought is Perspex.
DISCLAIMER: This is really early development pre-alpha-alpha stuff. Everything is subject to change, I'm not even sure if the performance characteristics of Rx make Observables suitable for binding throughout a framework. I'm writing this only to see if the idea of exploring these ideas appeals to anyone else.
Take a look at the introduction document here.
NOTE: This uses proposed C#6 features so you'll have to install a Roslyn preview. If you're using VS2013, try here.