Compare Mattermost and Quassel IRC on pricing, features, platforms, and ratings — both Team Chat tools, Freemium vs Free and open source under the GNU General…
At a Glance
Mattermost
Quassel IRC
Primary category
Team Chat
Team Chat
Rating
Not documented
Not documented
Pricing model
Freemium
Free and open source under the GNU General Public License (GPL-2.0 and GPL-3.0); there are no paid tiers or commercial licenses.
Starting price
Free (Starter, self-hosted); Professional from $10/user/month
Free
Free plan
Yes
Not documented
Free trial
Not documented
Not documented
Platforms
Web, iOS, Android, Mac, Windows
Android, Mac, Windows
Team collaboration
Not documented
Not documented
AI features
Not documented
Not documented
Public API
Not documented
Not documented
Pricing Compared
Starting price reflects the lowest paid tier, not the full cost for every team size or usage level.
Mattermost
Starter — Free N/A
Professional — $10/user/month annual
Enterprise — Custom annual
Quassel IRC
Open Source — Free N/A
Pros & Cons
Mattermost
Pros
Fully open-source core with self-hosted and air-gapped deployment options
Strong fit for regulated industries, government and defense customers
Playbooks provide built-in workflow automation not native to Slack
Deep integrations with developer and DevOps tooling
Lightweight architecture (single Go binary) makes self-hosting comparatively simple
Cons
Smaller app/integration marketplace than Slack or Microsoft Teams
Enterprise pricing is custom-quoted and not publicly transparent
Self-hosting requires ongoing server maintenance and updates
UI and mobile experience is generally considered less polished than Slack
Annual prepaid billing only for official Professional and Enterprise licenses, no monthly option
Quassel IRC
Pros
Completely free and open source with no paid tiers
Always-on core keeps chat history and presence intact across disconnects
Supports many simultaneous IRC network connections
Native cross-platform clients plus community mobile apps
SSL-encrypted core-client connections for security
Long-standing project with a stable, established codebase
Cons
Requires running and maintaining a core process on an always-on machine or server
Development pace has slowed, with the last major release in January 2022
Setup is more involved than single-binary IRC clients for newcomers
User interface feels dated compared to modern chat applications
Mobile clients are community-maintained rather than official first-party apps
No built-in support for chat protocols beyond IRC
Use Cases
Mattermost
Incident response and DevOps workflows — Engineering teams use Playbooks to coordinate incident response with automated checklists and dedicated channels.
Regulated and government communication — Public-sector and financial-services organizations need self-hosted or air-gapped messaging to meet compliance requirements.
Secure internal team chat — Organizations that want Slack-like messaging while keeping full control of where data is stored.
Quassel IRC
Always-connected IRC for open-source communities — Developers and maintainers who participate in project IRC channels use Quassel to stay continuously connected and never miss discussion, even when switching devices.
Self-hosted alternative to bouncer-plus-client setups — Users who previously ran a terminal client inside screen or tmux with a separate IRC bouncer use Quassel to get the same always-on behavior with a graphical interface built in.
Small team internal chat over IRC — Small technical teams that standardize on IRC for internal communication use Quassel so team members share a persistent, synchronized view of channel history.