Microsoft contributes Hyper-V drivers to the kernel

I think that it's worth considering.

Although I'd wish people would take a bit more of a consideration when understanding the scope of the problem with software patents.

For this example... The drivers are, I am guessing, are I/O drivers that implement some paravirtualization features to increase the performance and compatibility of running Linux in Hyper-V.

Well those patents that Microsoft may possibly have that covers some of the Hyper-V paravirt features may apply to the Linux driver code. But it's pretty likely that any patents would apply to paravirt techniques used in the Linux-KVM stuff or in Xen stuff.

So getting Microsoft to contribute code to the kernel means that not only are they probably sacrificing much of their ability to go after paravirt features used in KVM or Xen, it is quite likely a gain for Linux kernel in other ways.

Microsoft would put itself in a particularly tenuous legal position and likely destroy their ability to sell software to companies with legal departments if they distributed code under some license and then sued people for patent infringement for using that code under that license. Can any Microsoft software be used at all without violating a Microsoft patent which the purchaser has not explicitly granted a license to? (Particularly as the licenses for new software may be written too soon to have explicit references to new patents the software uses.)

IBM holds several patents applicable to Linux (RCU, some JFS stuff) and nobody cares, even though they forced PostgreSQL guys to remove some stuff because of some patent IBM holds. But of course IBM (which was, btw, the first large company to use FUD as a marketing strategy, against Amdahl - oh, and there is the Platform Solutions case) is nice and Microsoft is evil.

;->