Red Hat and Mirantis, once an OpenStack couple, have split by Barb Darrow @FortuneMagazine July 1, 2015, 5:20 PM EDT E-mail Tweet Facebook Linkedin Share icons Back in the day, say oh, two years ago, Red Hat RHT and Mirantis were tight. At least tight enough that Red Hat plowed some cash into Mirantis as part of a $10 million Series A funding round. That investor/startup relationship has ended. But let’s back up. Initially, the Red Hat-Mirantis hook-up made sense. Red Hat is the leader in enterprise Linux with an interest in pushing OpenStack cloud infrastructure; Mirantis was a systems integrator specializing in real-life OpenStack deployments. Mirantis would go into a customer and knit together the best OpenStack components, often from many vendors, into a solution that actually did work. Win-win. But that was then and this is now. In the interim, Mirantis morphed from an OpenStack integrator into an OpenStack vendor that offered its own version of the open-source cloud framework. And that was a problem for Red Hat, which pushes its own flavor of OpenStack. The two partners became competitors, and you know how that goes. A year ago, Red Hat bought eNovance, which is, you can probably guess, an OpenStack systems integrator. There were some PR skirmishes and by September, it was clear that Mirantis wanted to buy Red Hat out. Or that Red Hat wanted to be bought out, depending on your point of view. In October, Red Hat was not among the companies participating in a massive $100 million investment round in Mirantis, although it was still listed as an investor. A few months later, Red Hat’s name disappeared from Mirantis’ press releases. Shame on me for not noticing this omission sooner. Reached for comment, Mirantis co-founder and chief marketing officer Boris Renski confirmed that Red Hat is no longer an investor in his company but declined to provide details. He added that the two companies continue to work together and support joint customers. Fortune reached out to Red Hat for comment and will update the story when needed.