As I understand it, in Windows Explorer even the part that we use to browse around the contents of the C: drive is a namespace extension.
Namespace extensions are used by various vendors to display information related to their solution. web.de uses them to display the contents of the user’s WebDAV webspace at web.de. Mobile phone vendors can use them to display the contacts in mobile phones.
Filesharing solutions such as groove can use them to display the shared files in a way familiar to the user.
As we can see, namespace extensions have a wide range of applications, a lot of innovation around them seems possible.
Despite their usefulness and wide range of possible applications, developing namespace extensions is not trivial. This is due to the following points:
- They must be written in C++ for practical reasons (Delphi, Visual Basic and others are impractical as using them is not mainstream, so you have nowhere to go when stuck, and you’ll hardly find solutions for doing things that are common to do in C++, if only to access a certain Windows API function; writing namespace extensions in .NET is not a technically sound option, it is unstable by definition when two shell extensions demand different versions of the .NET runtime libraries)
- To write them Microsoft COM know-how is required
- To write them know-how about foreign, arcane concepts are necessary, such as PIDLs
- If you screw up (and unfortunately C++ makes that very easy), Windows Explorer crashes or becomes unusable
My current employer outsourced development of a custom namespace extension that displays the contents of a folder in it. The goal was to mimic Windows Explorer’s look & feel and functionality as closely as possible. The outsourcing partner has developed a helper framework for development of namespace extensions and has gathered a lot of C++ and Windows system programming know-how over the years.
Sounds like a safe bet? Nope. The partner had a lot of trouble preventing the namespace extension from plain crashing on Windows Vista. After several weeks and numerous updates to his core product and our customised solution based on it it even turned out that the problem existed on Windows XP, it just didn’t surface as easily yet. Eventually, he managed to fix the crashes. He has done a good job and in the process improved functionality and stability of his own product, so apart of the monetary benefit of working for us, he can walk away with a better product now, and a few new items in his know-how bag.
While the outcome is satisfactory, the process to get there raises a few questions:
- Why does it take a professional software product developer weeks to fix crashes in his core namespace extension?
- Why doesn’t Microsoft offer a way to write namespace extensions with something more productive than C++?
- Why doesn’t Microsoft offer a way to write namespace extensions with scripting languages?
Microsoft hinders innovation by making writing namespace extensions extremely hard, and by not offering to write namespace extensions with scripting languages.
