WriteableBitmapEx is still quite popular, especially with WPF developers and I always incorporate bug fixes and also accept Pull Requests if I get some time.
Many contributions were integrated and lots of bugs fixed. Among those are some nice additions like a clipped line drawing or a dotted line renderer.
WriteableBitmapEx supports a variety of Windows platforms and versions: WPF, Silverlight, Windows 10 Universal Windows Platform (UWP), Windows 8/8.1, Windows Phone WinRT and Silverlight 7/8/8.1.
You can download the latest via the updated NuGet package. The packages contain the WriteableBitmapEx binaries. All samples and the source code can be found in the GitHub repository.
A big thank you to all the contributors, bug reporters and users of the library who help with feedback.