That's the question I had not thought of asking, nor really given much thought to at all, until now. What prompted the question was the appearance of the Official Engineering Windows 7 blog.

The third posting proved to be a fascinating read, providing the kind of insight into the development of a software project as large as Windows that frankly is hard to get anywhere else. This is real horse's mouth stuff. Steven, writing on behalf of the Windows E7 team, says simply that none of the posts are ghost written by the PR department but instead he is "typing this directly in Windows Live Writer and hitting publish. This blog is the real deal—typos, mistakes, and all. There’s no intermediary or vetting of the posts."

Which is cool.

But not as cool as the detail revealed about that team which is developing Windows 7.

"Rather than think of one big org, or two teams, we say that the Windows 7 engineering team is made up of about 25 different feature teams" Steven says, continuing "A feature team represents those that own a specific part of Windows 7—the code, features, quality, and overall development. The feature teams represent the locus of work and coordination across the team."

How big is a feature team? It varies, but the average is 40 developers per team. Each of these work on parts of the platform which have familiar sounding names. "In general a feature team encompasses ownership of combination of architectural components and scenarios across Windows" we are told.

Some of the main feature teams for Windows 7 include:

• Applets and Gadgets
• Assistance and Support Technologies
• Core User Experience
• Customer Engineering and Telemetry
• Deployment and Component Platform
• Desktop Graphics
• Devices and Media
• Devices and Storage
• Documents and Printing
• Engineering System and Tools
• File System
• Find and Organize
• Fundamentals
• Internet Explorer (including IE 8 down-level)
• International
• Kernel & VM
• Media Center
• Networking - Core
• Networking - Enterprise
• Networking - Wireless
• Security
• User Interface Platform
• Windows App Platform

Which brings me nicely back to that original question, and the answer we now know is at least 25 x 40, or 1000 developers at the very least.