In his blog post Windows DVD Maker Not Managed Code Charles Cook writes

Last week Eric Gunnerson mentioned that he has been working on an application for Vista: Windows DVD Maker. Yesterday he posted a FAQ for the application. The answer to question 4 was disappointing:

4: Is DVD Maker written in managed code?

A: No. Yes, it is ironic that I spent so much time on C# and then spent a ton of time writing something in C++ code. Everybody on the team is a believer in managed code, and we hope we'll be able to use it for future projects.

Given that there is a whole new set of APIs in Vista for writing managed applications - Avalon, WinFX, etc - why has a new self-contained app like this been written in unmanaged C++? Actually writing real applications, instead of just samples, with the new managed APIs would be far more convincing than any amount of hype from Robert Scoble.

I agree with Charles. If Microsoft believed in managed code, we would build applications using the .NET Framework. We do.

In his post Cha-Cha-Changes Dan Fernandez wrote

The Microsoft's not using Managed Code Myth
One of the biggest challenges in my old job was that customers didn't think Microsoft was using managed code. Well, the truth is that we have a good amount of managed code in the three years that the .NET Framework has been released including operating systems, client tools, Web properties, and Intranet applications. For those of you that refuse to believe, here's an estimate of the lines of managed code in Microsoft applications that I got permission to blog about:

• Visual Studio 2005: 7.5 million lines
• SQL Server 2005: 3 million lines
• BizTalk Server: 2 million lines
• Visual Studio Team System: 1.7 million lines
• Windows Presentation Foundation: 900K lines
• Windows Sharepoint Services: 750K lines
• Expression Interactive Designer: 250K lines  
• Sharepoint Portal Server: 200K lines
• Content Management Server: 100K lines

We also use managed code for the online services that power various MSN Windows Live properties from Windows Live Messenger and Windows Live Mail to Live.com and Windows Live Expo. I find it surprising that people continue to think that we don't use managed code at Microsoft.