Mattermost

Team communication and collaboration platform

Alternative to: Slack, Microsoft Teams, Discord

GitHub stars 38,340

About Versions (141)

v11.5.4

2026-04-22

Mattermost Platform Release 11.5.4 contains medium to high severity level security fixes.

WinterFlow.io — Fresh look at Self-Hosting.

Be the first to deploy your apps — join the WinterFlow waiting list.

Email address

We'll send early access invites when it's ready, along with occasional product updates — no spam, ever.

Get early access to our Business Plan with collaboration features, team apps, and advanced management capabilities.

Email address

We'll notify you when Business Plan becomes available, plus occasional updates about team features.

I'm interested in participating in a user interview

Help us build better team features by sharing your workflow and needs (optional, 15-30 min call)

Skip the server setup entirely. We'll provide fully managed infrastructure so you can deploy apps instantly.

Email address

No spam, just early access invites and product updates.

Get notified when this app is ready to install on WinterFlow.io

Email address

We'll only email you about this app's availability.

Let us know what app you're looking for and we'll consider adding it to our catalog.

Email address

We'll only contact you with updates about this request.

Expected app name