Community MX has just released an article about the structure of their CMXtra Central application. It discusses the architecture and who the files are structured, and goes into specific features such as using tooltips, the local file cache and and LCServer.
However, the coolest part of the article is that they have made all of the source code for their CMXtra application available. This is an excellent resource for looking through the code of a complete application and learning how all of the parts fit together.
You can read the entire article here.