Would it be possible to move your extension methods for System types into their own namespace? Something like UIWidgets.SystemExtensions ? The reason I ask is because ... well I guess great minds think alike. I frequently get errors like this. The call is ambiguous between the following methods or properties: 'UIWidgets.Extensions.ForEach<T>(System.Collections.Generic.IEnumerable<T>, System.Action<T>)' and 'Sage.Designer.Unity.Extensions.IEnumerableExtension.ForEach<TValue>(System.Collections.Generic.IEnumerable<TValue>, System.Action<TValue>)' If you moved your System extensions into a separate namespace they are still usable with a simple using. it will let me bring everything in but them and use my extension methods for System types. I know this is nit picky.. I was just hoping in a future release this might get this addressed.