Mattermost

★ 4/5 · Other

Open-source, self-hosted team messaging and collaboration platform built for security-conscious organisations that need full control of their chat data.

Pros

Self-hosted Slack alternative with 38k+ stars and active development
comprehensive feature set (chat, calls, video, screen sharing, AI integration)
strong privacy/compliance for enterprises

Cons

Requires infrastructure deployment and maintenance
enterprise features and advanced integrations behind paywall
complex setup vs. SaaS alternatives

Cost

Free open source (MIT); optional Mattermost Enterprise license and cloud hosting from $X/month available

Verdict

Teams and enterprises prioritizing self-hosted collaboration with full data control and customization capabilities.

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