Just a few months ago, we partnered with Mattermost and led the Series A. We believe that open source applications will be an important part of the future of software because of their security, lower costs of customer acquisition and the flexibility they offer customers.

Today, Mattermost is announcing a $50M Series B from Y Combinator Continuity and Battery. I’m thrilled to partner with Ali Rowghani from Y Combinator and Neeraj Agarwal from Battery for the next leg of the journey. They both share the same vision of open source application software changing the enterprise landscape.

Customer after customer connects Mattermost to their most important systems. Often, these systems are invisible to the Internet. Security operations teams create air-gapped networks for incident response, operations teams developing workflows to fetch logs from different systems to remediate outages, and IT teams developing powerful workflows to automate inbound support tickets from their users - all on Mattermost.

Mattermost’s momentum is a result of tremendous developer adoption. Developers love the product because they can customize it. They modify the UI to incorporate key development and deployment metrics, embed Mattermost chat into internal applications, and rich communication support for gifs and emojis.

And because it’s written in Go and compiles to single binary, Mattermost installs and upgrades easily. Just copy a single file to your server. And it scales and scales handling tens of thousands of concurrent requests.

The collaboration market is measured in the tens of billions. Enterprise buyers’ increased desire for data control, compliance and security signifies a substantial chunk of that market is addressable by open source. Mattermost’s Series B is another step forward to fulfilling that ambition. Congratulations to the team on another great milestone.