ExchangeLinq is a LINQ Query Provider for the Stack Exchange API. It only supports API v2.0. It is currently in alpha state and is being developed for Exchange It, a Stack Exchange client for Windows Phone.
ExchangeLinq doesn't do the OAuth process. You need to implement this yourself, for example by using a browser control.
ISiteStackExchangeContext context = StackExchangeContext.Create(<apiKey>, <apiSiteParameter>); IStackObservable<Question> questions = from q in context.Questions select q; questions.Subscribe(...);
The syntax is very intuitive and you get full intellisense support in visual studio.
.NET 4, Silverlight 4 and 5 and WP7.1 (Portable Library coming soon)
Feel free to contact me via my blog or to contribute by opening pull requests on github.