Why it matters: There's been plenty of friction between Microsoft and the open source advocates regarding patents over the years. By joining the Open Invention Network, Microsoft is taking a big step in improving relations with the community.

Microsoft is open-sourcing its vast patent portfolio. On Wednesday, it was announced that the Redmond-based technology giant had joined the Open Invention Network (OIN), the largest patent non-aggression community in the world with more than 2,650 members.

Corporate Vice President and Deputy General Counsel Erich Andersen said Microsoft brings more than 60,000 issued patents to OIN. According to ZDNet, Microsoft's entire patent portfolio is on offer with the legacy exception of its Windows and desktop application code.

The patents, as well as those on offer from other members including Google, IBM, Sony and Philips, are available to license royalty-free to anyone that joins the OIN community.

This isn't Microsoft's first step towards being more open. Programs like Azure IP Advantage, for example, extended patent protection to Azure service users more than two years ago.

Still, it's big news. OIN CEO Keith Bergelt said it covers "everything related to older open-source technologies such as Android, the Linux kernel, and OpenStack; newer technologies such as LF Energy and HyperLedger, and their predecessor and successor versions."

In 2013, Microsoft collected $3.4 billion in licensing fees related to its Android patents. What sort of impact will the OIN development have on revenue from licensing deals?

Earlier this month, Microsoft released the source code for MS-DOS on GitHub, the code repository it purchased earlier this year for $7.5 billion. It had previously been available through the Computer History Museum although it wasn't quite as easy to find through that source.