IF we’re talking .NET, try Scripting .NET applications with VBScript over on CodeProject. Lots of concrete examples there.
Below are sites implementing various application extension techniques
- ClearScript – Makes V8, VBScript and JScript available to .NET apps
- CS-Script – The C# Script Engine
- Plugin Architecture using C#
- Opinio plugin architecture
- Notes on the Eclipse Plug-in Architecture
- Plug-in Architecture Framework for Beginners
- Gecko plugin architecture
- Fungimol plugin architecture