However, with regard to my new hobby of extracting reusable patterns from apps I’m building, I really appreciate the idea of extracting these patterns into small, reusable and interoperable parts. In the Future of Programming panel, Jeremy Siek noted the importance of libraries working with other libraries (e.g., ASP.NET with ASP.NET MVC or ASP.NET AJAX with many Javascript libraries). Some libraries, however, implement their patterns too tightly around certain patterns to the exclusion of others. This can increase speed—Ruby on Rails comes to mind—but removes the ability to use other patterns or pluggable libraries–such as with Merb or Ramaze–to keep to the Ruby frameworks.

JB and I are attempting to extract patterns from our current project to enable faster development in future WPF/Silverlight projects. The current plan is to build our library around Composite WPF, an excellent library from Microsoft’s Patterns and Practices group for building rich client applications in WPF, and soon in Silverlight. We’re planning to build a business layer framework with service interfaces to the Composite WPF library and use the Repository pattern to allow for various data access methodologies.

That’s a loose description of our plan. What do you think? Do you see any flaws? For instance, we are currently not thinking about interchangeable UI libraries, even though a few, such as Silverlight.FX, have started to appear. Are we missing any existing business layer libraries? (I am not familiar with any myself, but I imagine someone has created one somewhere.) We are interested in your thoughts!