Mary Jo has the headline -- "Pigs do fly" -- that captures Microsoft's contribution of 20,000 lines of code to the Linux kernel community.

The contribution was announced today at the OSCON open-source conference in San Jose, Calif.

It's the latest effort by Microsoft to present itself as enlightened and respectful toward the nemesis used by many of its enterprise customers, while at the same time making Microsoft's virtualization software more valuable to them.

Here's how Tom Hanrahan, director of Microsoft's Open Source Technology Center, described it in prepared press material:

Today we're releasing Linux device driver code to the Linux kernel community. This is a significant milestone because it's the first time we've released code directly to the Linux community. Additionally significant is that we are releasing the code under the GPLv2 license, which is the Linux community's preferred license.

Our initial goal in developing the code was to enable Linux to run as a virtual machine on top of Hyper-V, Microsoft's hypervisor and implementation of virtualization.

The Linux device drivers we are releasing are designed so Linux can run in enlightened mode, giving it the same optimized synthetic devices as a Windows virtual machine running on top of Hyper-V. Without this driver code, Linux can run on top of Windows, but without the same high performance levels. We worked very closely with the Hyper-V team at Microsoft to make that happen.