Microsoft and SUSE announced on Monday a four-year extension of their interoperability agreement.

The agreement covers a collaboration effort to ensure Windows and Linux work well together and are supported by each firm. The new agreement means the relationship between the pair will extend to January 1, 2016. Microsoft has agreed to invest $100 million in a new SUSE Linux Enterprise certificate for customers receiving support from SUSE.

“Our collaboration with SUSE not only helps customers to achieve success today, but also seeks to provide them with a solid foundation for tomorrow,” said Sandy Gupta, general manager of the Open Solutions Group at Microsoft. “Through our continued engagement on the technical side, an outstanding support offering from SUSE and our ability to provide mutual IP assurance, we feel confident that we will be able to deliver core value to those running mixed-source IT environments well into the future — and into the cloud.”

Microsoft and SUSE plans to push their technologies into the cloud, virtualization and manageability products. Microsoft also plans to extend its System Center through integration with SUSE Manager to improve Linux deployment, patching and updating.

The agreement comes days after Linux celebrated its 20th birthday. Microsoft sent a Happy Birthday video to the Linux Foundation entailed “Microsoft vs Linux”. The video was a comic history of the pairs competitive nature.