OpenRasta is an open-source .NET framework for building everything web, from web sites to RESTful APIs
Written from the ground-up with testing in mind, OpenRasta removes the faff from your code and lets you concentrate on writing clean, beautiful code.
Proven in the real world, OpenRasta is the perfect choice for building scalable, high-performance, reliable web services.
To install via OpenWrap command line:
o add-wrap openrasta-devtools -sys
Or you can install using NuGet
Find out more
Sebastien Lambla, the creator of OpenRasta, writes about the project in his blog at CodeBetter.com.
There is a wiki at GitHub. You should probably follow seb on twitter as well!