Mattermost CEO here, Awesome work on raspchat! And thanks for the kind words. Often we see users and customers have both Microsoft Teams for Office365 users

Mattermost CEO here, Awesome work on raspchat! And thanks for the kind words. Often we see users and customers have both Microsoft Teams for Office365 users and Mattermost as the "developer's choice" given the open source code base and flexibility in high security environments. Per the article, the market is very large, and there's many different user segments to serve. Therefore there should be multiple winners here, in my mind. I think this category is only just starting.