This document summarizes a talk on Spark on Mesos given by Dean Wampler from Lightbend and Timothy Chen from Mirantis. It discusses why Spark on Mesos is useful by allowing one cluster system to run multiple tools. It then covers recent updates like a new integration test suite, coarse-grained scheduler improvements, and Mesos framework authentication. Finally, it outlines future plans such as GPU support on Mesos and making "production" use of Spark on Mesos easier.