Mesosphere, the company commercializing the Mesos resource manager announced their Series C funding.   The Mesos project started in the UC Berkeley RADLab and was further developed in the AMPLab.   Spark was one of the first frameworks written to run on Mesos.   The press release states:

Mesosphere DCOS [Data Center Operating System] is the first major operating system introduced since Android, and the first ever operating system purpose-built for datacenter-scale systems and applications. The open source core of DCOS, Apache Mesos, originally gained prominence as the key technology that killed the Fail Whale at Twitter, and was the platform on which Apache Spark was built at the University of California at Berkeley, AMPLab.