Since the first public news of Windows 7's development back on October 2007, we've heard about a component of the operating system called MinWin -- a tantalizingly titled element that sounds like some kind of portable Windows kernel. Now Windows 7 is actually residing on paying consumers' desktops, and inside of it -- and inside of Windows Server 2008 R2 -- is the MinWin kernel architecture...and yet few have been made clear as to what it actually is.
A few weeks ago in Los Angeles, Microsoft technical fellow Mark Russinovich -- absolutely the world's leading authority on Windows performance and architecture -- took time to explain to developers attending PDC 2009 in Los Angeles exactly what this is. In summary, it's a way to graft onto Windows some semblance of the architectural layering it should have had, if its architects in the 1980s had any foresight into how Windows would be used thirty years later. It enables current and future Microsoft developers to evolve new configurations of the operating system, without having to rewrite core services or worry about breaking dependencies between those services and upper-level APIs.
"If you look back at the evolution of Windows, it's evolved very organically, where components are added to the system and features are added to the system without, in the past, any real focus on architecture or layering," Russinovich explained. "And that's led us to do some hacks with Windows, when we want to make small footprint versions of Windows like Server Core, or Embedded Windows, or Windows PE -- the pre-installation environment. What we do [instead] is take full Windows, and start pulling pieces off of it. The problem with that is, the pieces that are left sometimes have dependencies out to the pieces that we've removed. And we don't really understand those dependencies."