It is more optimal for handwritten content compared to SVG, and provides uniform graphical representation across devices, unlike InkML.
Yes, inking tools are entirely parameterized and application developers can design their own tools. The developers can define the width and opacity of the inking tools. The rendering parameters (textures, blend modes, etc.) are also configurable.
The inking view appears in SurfaceView or TextureView on Android; CAEAGLLayer on iOS; SwapChainPanel on Windows 8; and HTMLCanvas on Web.
Any development environment for the supported platforms is generally suitable. However, the Demo Projects provided require the following IDEs: 

- Eclipse ADT for Android 

- XCode 5 for iOS 

- Visual Studio 2013 or higher 

-Windows 8.1 or higher

Yes, images can be imported to the WILLTM canvas as OpenGL/DirectX/WebGL textures.
No, WILLTM is designed to work with any kind of pointer input device, or even your finger!
WILLTM SDK proves built-in support for .will, the WILLTM stroke file format.
For approximately one hour of handwriting with a solid color ink on iPad3 Model MD331FD/A, the performance stats are: 
  • File size: 1103 KB 
  • Strokes count: 9353 
  • Total control points count: 194,090 
  • Total time for loading file and rendering: ~3.595 seconds 
  • Loading and processing of stroke file format: 1.154 seconds 
  • Render time only: 2.441 seconds

If you have further questions about file compatibility for your existing application or anything else, please contact us at willdevelopers@wacom.com.

For approximately one hour of handwriting with a solid color ink (9,353 strokes have 194,090 total control points), the file size would be ~1.1 MB.
Yes. Using the class WCMBezierPathUitls on iOS; Module.BezierPath on Web; BoundaryBuilder on Android; the ink can be converted to a Bezier curves path, describing the boundaries of the ink. With this path, the developer can produce SVG or PDF, using a suitable API for his platform.