Microsoft resources

Here are the most important and relevant articles from Microsoft about Shell Namespace Extension programming, and how do they relate to ShellBoost concepts:

Common Explorer Concepts covers the IDL / PIDL concept. ShellBoost also uses PIDLs for identifying shell items as this is not really an option, but through easy to use .NET classes: ShellItemId and ShellItemIdList available in the ShellBoost.Core.dll assembly.

Understanding Shell Namespace Extensions is a must read, event for ShellBoost users as it explains the general Shell concepts.

Implementing the Basic Folder Object Interfaces is another introduction more detailed to shell namespace extensions.

Specifying a Namespace Extension's Location explains junction point.

Using the search Protocol details the search protocol.

Windows Property System introduces the Windows Property System.

How to Display a Rooted View of a File explains the registry setup for virtual files.

Note there any many other articles on the Internet from Microsoft on Shell Namespace Extensions that are not listed here in this documentation because their subject is covered otherwise by ShellBoost or it’s not relevant when using ShellBoost and its out-of-process architecture.