Initially Silverlight Composite UI Applicatin Block (SCAB) was designed to work with Silverlight 1.1 alpha. Application architecture was redesigned in Silverlight 2.0 beta 1 significantly. And now SCAB should be redesigned to provide compatibility with new Silverlight.

The new idea is to update SCAB which was initially designed like CAB with new technologies such as Acropolis and Prism to get more extensible clearer and lightweight Silverlight oriented technology. The second idea is to break standard Microsoft approach in Silverlight application packaging to get more extensible architecture.

The first idea can be implemented for example including RegisterType, RegisterInstance and Resolve methods into WorkItem class instead of Services and Workspaces properties. Acropolis can give Part, PartView, PartPane, LayoutPane classes to make object model clearer and enable WPF specific.

The second idea is to exclude App.xaml from application assembly into Xap package to enable application resources configuration on the fly by ASP.Net. Now XAP packaging is simple after Xap archiver was released in the Elisy.Web assembly. App.xaml will contain module definitions in resources as well.