Chat vs Slack
Chat and Slack are both team chat software. Chat is open source under GPL-3.0, with 14k GitHub stars. Slack is a commercial product from Salesforce, Inc.
Which to pick
- Pick Chat when
- You want to embed or run your own messaging service with ready clients.
- Pick Slack when
- A team wants the chat tool with the widest integration ecosystem and is willing to pay per seat.
Side by side
An instant messaging server in Go with web, Android and iOS clients, group chats and a chatbot API.
Team messaging organised into channels and threads, with huddles, shared channels between companies, workflows and thousands of app integrations.
Still pre-1.0 after many years, with a small team.
Per-seat pricing is high, the free plan hides history older than 90 days, and Salesforce keeps tightening API access.
Usable
Production-ready
Self-hosted server and mobile app
Cloud service, desktop app and mobile app
Go, PostgreSQL, MySQL and MongoDB
Not published
Open source, GPL-3.0 (strong copyleft)
Closed source, sold by Salesforce, Inc.
Use inside your business is unrestricted, but anything you distribute that includes it must be released under the same license.
Closed source: you use it under the maker's terms and cannot change or resell the code.
14k GitHub stars
8.4k Wikipedia readers a month on phones
Established: started 12 years ago, latest release v0.25.3.
Not known
Other comparisons
More team chat apps
Both sides were judged on 2026-11-03 from makers' descriptions, Wikipedia, READMEs and GitHub data. License, age and popularity lines are worked out directly.