Porter: Rethinking the Library OS from the Top Down

Porter, Boyd-Wickizer, Howell, Olinsky, Hunt (2011)

What kind of paper is this?

The Fairy Tale: Once upon a time the folks from MIT proposed implementing most of an operating system in a library that could be linked directly with applications. Their emphasis was on providing direct access to hardware to improve performance. This approach fell out of favor as virtual machine (VM) computing took over the world. However, VMs are large and consume a lot of resources. Drawbridge takes the idea of combining applications with OS APIs (but not the direct management of hardware) to produce unikernels that are much smaller than VMs, but provide similar advantage: isolation, migration, and packaging. They demonstrated this approach using a large commercial OS (Windows 7) and convinced the world that if they adopted this approach, everyone would live happily ever after.

The Story


Windows 7


Drawbridge ABI

Process of Porting Windows 7 to libOS


  • Security patches: unsurprisingly (and perhaps unfairly), libOS requires fewer security patches. (Unfairly, because it does not implement everything in the base system.)