Mattermost
#7 in Business Communication · Rated 4.1
Open, secure, configurable team messaging for developers and ops
Mattermost is an open-source, self-hostable team messaging platform designed for security-conscious organizations. It supports chat, file sharing, and workflow automation with deep integration hooks and enterprise-grade deployment options (self-hosted or private cloud). Mattermost is widely adopted in mission-critical contexts (defense, finance, government) where data sovereignty and customization matter. The product differentiates itself from SaaS-first rivals by offering on-prem or private cloud deployments with strong governance and audit capabilities. In 2025, Mattermost continued to emphasize secure collaboration for critical infrastructure teams while maintaining cloud offerings.
Features
- Self-hosted or private cloud deployment
- Real-time chat and file sharing
- Audio/screen sharing
- Workflow automation
- Deep interoperability with Microsoft Teams, Outlook, and more
Pros
- Strong security and deployment flexibility
- HIPAA/DoD-friendly guidance for certain deployments
- Open-source roots and extensibility
Cons
- May require more in-house IT to operate self-hosted
- UI and UX can feel less polished vs SaaS-first competitors