Balder started off in 2007, at the same time as Silverlight 1.1 Alpha was released. The goal back then was not to create a project like Balder has evolved into today, but rather just prove that 3D would be possible with Silverlight.
Now, almost 4 years later, this goal has changed quite a bit. Today the primary objective for the library is to create a library that is really easy to use, with little or no 3D knowledge or experience up front and bring it primarily to Silverlight and Windows
Early on, Balder was architected with multiple platforms in mind, and this architecture now proves very handy. Porting Balder to Windows Phone 7 took around one day to accomplish the basics.
The overall dream is to be able to create a library that can work on multiple platforms, including iOS devices, Android devices, desktop environments on Windows, OSX and Linux through WPF, Xna and OpenGL - this in addition to Silverlight and Windows Phone 7.
One benefit that can be drawn from the different implementations is reusing code. Since Windows Phone 7 uses Xna and Xna is also available on Windows, the code will therefor be written in a fashion that makes it possible to reuse the elements. This also applies
to the OpenGL implementation; OSX, Linux and iOS all support OpenGL and share abstractions for .net. MonoDroid is also a OpenGL device and will eventually have the same abstraction as the other mentioned.
Not everyone likes to do their visuals in code or in Xml by hand - therefor it is very important that Balder gets full design-time support in tools like Microsoft Blend and Visual Studio 2010. This is something missing as of December 2010, but will be in focus
Another aspect of the design-time support is the support for Blends interactivity, which consists of actions, triggers and behaviors. Its a clear goal for Balder to add Balder specifics for this. That will give the ability to do a lot by drag'n'dropping
inside tools like Blend.
Today (27th of December 2010), Silverlight does not have hardware accelerated 3D support. With the launch of Silverlight 5 in 2011, hardware support will be added. This is something that Balder will support as well.