Cloud computing startup Mesosphere made its mark early with large companies like Twitter and Netflix, and on Thursday the company got a fresh boost from two more tech giants: Microsoft and Hewlett Packard Enterprise. Built on the open-source Apache Mesos project credited with helping Twitter kill its “Fail Whale,” the company has closed US$73.5 million in a Series C funding round led by HPE, with participation from Microsoft as a new strategic investor. Designed to help enterprises build microservices-based applications, run big-data systems and operate massive production container environments, Mesosphere’s Datacenter Operating System (DCOS) is “the most exciting new enterprise operating system since Linux,” said Lak Ananth, managing director at Hewlett Packard Ventures, in a statement. HPE and Microsoft provided “the lion’s share” of the funds in this latest round, said Matt Trifiro, Mesosphere’s senior vice president, in an interview on Wednesday. The new infusion brings Mesosphere’s total funding to date to nearly $126 million. DCOS is used at a massive scale by customers including Verizon. It’s also a key component of Microsoft’s Azure Container Service. The open-source core of DCOS, Apache Mesos, was the platform on which Apache Spark was built as well. “Mesosphere is at the center of three of the biggest tech trends today: cloud, containerization and microservices,” said Scott Guthrie, executive vice president of Microsoft’s Cloud and Enterprise division, in a statement. DCOS is preferred by Microsoft’s enterprise customers because of the maturity of its container orchestration technology, he added. The strategic investment from HPE and Microsoft is “a validation of Mesosphere’s container orchestration and DCOS software,” said Jay Lyman, a research manager with 451 Research. Container scheduling, management and orchestration technologies are increasingly critical in enterprises, Lyman added. In addition to forming the basis for Microsoft’s Azure Container Service, DCOS will also soon run on Windows Server as well as Linux thanks to the collaboration between the two firms, Trifiro said. That technology is expected to enter beta later this quarter. Also on Thursday Mesosphere announced Velocity, a new product for continuous integration and deployment, as well as version 1.0 of its Marathon container orchestration platform.