[gmenegatti]

Rocket.chat is also a very nice alternative and supports more use cases. We use it internally and also as part of our product.

[oso2k]

I completely concur. We used Rocket.Chat (running containerized on OpenShift, our Kubernetes distro) for a time at Red Hat to support the bulk of Red Hat Consulting. Many thousands of messages per minute sustained throughput. All of Red Hat has "restandardized" in the last year but I personally miss Rocket.Chat.