Microsoft contributions

In July 2009 Microsoft contributed 20,000 lines of code to the Linux kernel. The contribution consisted of Hyper-V drivers, which improve the performance of virtual Linux guest systems in a Windows hosted environment. Microsoft licensed its Linux Hyper-V drivers under the GPL. Microsoft was forced to make the code contribution when Vyatta principal engineer and Linux contributor Stephen Hemminger discovered that Microsoft had incorporated a Hyper-V network driver, with GPL-licensed open source components, statically linked to closed-source binaries in contravention of the GPL license. Microsoft contributed the drivers to rectify the license violation, although the company attempted to portray it as a charitable act, rather than one to avoid legal action against it. To put this contribution into perspective, in 2001 at Microsoft's Annual Financial Analysts Meeting in Seattle, Microsoft CEO Steve Ballmer said that Linux has "the characteristics of communism"; in 2001 Ballmer in a media interview with the Chicago Sun-Times stated "Linux is a cancer".[17][18][19][20][21][22][23]

The Microsoft-contributed drivers were not supported by Microsoft and this left them at risk of being dropped from the kernel at version 2.6.33.[24] The prospect of the drivers being dropped did briefly result in Microsoft developers conducting more work to maintain the code, but their effort did not endure and their code is slated for removal as of kernel version 2.6.35.[25][26]