Communication
Zulip
Open source chat and collaboration software.
What it is
Zulip organises chat into topics inside channels, so conversations stay readable even when you were away for a day.
Strengths and trade-offs
What works well
- Topic threading makes catching up genuinely possible
- Open source and self-hostable
- Good for asynchronous, distributed teams
Where it falls short
- Topic discipline must be taught to the team
- Interface is denser than Slack
- Smaller integration ecosystem
Who it is for
Distributed teams that lose context in flat chat.
Our verdict
The threading model solves a real Slack problem. It only works if the team maintains it.
Closest alternatives we track
Same category, ordered by verified starting price.
Briar
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GroupMe
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Free Microsoft-owned consumer group messaging service for mobile and web, with chats, announcements, school communities and optional Copilot interactions.
Jami
Free
Free GPL-licensed peer-to-peer messaging, calling and conferencing software for desktop and mobile.
What we checked
- Public APIOffers a documented API you can build against.Not checked
- Mobile appHas a native app for iOS or Android, not just a mobile website.Not checked
- Open source / self-hostableSource is open and the tool can be run on your own infrastructure.Not checked
- SSO (SAML)Supports SAML single sign-on on at least one plan.Not checked
“Not checked” means exactly that — we have not verified it, and we do not guess.
Evidence and freshness
Status: Vendor pricing page verifiedReviewed: 2026-08-31
- Zulip — Pricing ↗
Checked 2026-08-31 · Supports: the vendor's published pricing
Limit: Automated check: the pricing page was fetched on this date and contained pricing information. An editor has not read it line by line.