Things have changed a lot since Ballmer said that. Microsoft has been a big contributor to Linux over the past several years, primarily focusing on improving support for its Hyper-V hypervisor.
Jim Zemlin, executive director of the Linux Foundation, said that in becoming a member, "Microsoft is better able to collaborate with the open source community to deliver transformative mobile and cloud experiences to more people".
What is surprising many is how good an open saucy citizen Vole is. It not only publishes source code repositories that are occasionally updated from an internal development branch, but performing development in the open, accepting community contributions and seeking community consensus when it comes to new features.
That is not the only strange “joining” news this week. Google is joining the .NET Foundation and will be part of the Steering Group.
Google has shown little interest in .NET and, with Android, is Java through and through. But there are forces within Google who want to improve .NET support in Google Cloud Platform. This will give the outfit more clout in the corporate market.