Classic ASP Page Framework
The other day I asked a question on a list about the perf. Implications of using VBScript classes in classic ASP applications. After participating in that thread I was reminded that, a while back I actually wrote an object oriented, event-driven classic ASP Page model which mimics some of the services which are built into the ASP.NET pages - such as Authentication, Users/Identities and Page properties. The page automagically serializes it's state (which could be abstracted by implementing a Provider model). The model also contained an in-built AuthenticationProvider which handles re-directs when secured resources are requested.
The whole framework weighed in at less than 350 lines of code! You can see the code for it here:
http://flws.com.au/AuthenticateModel.html
For me one of the big things about abstracting things into object models is that, because people relate to objects well object - such as Person.MiddleName - they enable you to easily build robust frameworks by pushing essential services down a layer. It's only through building reliable frameworks that you can achieve true manageability - especially when project sizes need to be be scalable.