Terms of use
Last updated: 11 October 2026.
The Antimatter software
Antimatter is free software. You may use, study, change and share it under the terms of its licenses: the GNU Affero General Public License v3.0 for the server, and the Apache License 2.0 for the web app, the server's templates and translations, and its public packages, as described in the license file. Those licenses are the only terms that apply to the software.
As the licenses state, the software is provided "as is", without warranty of any kind. The organisation that runs an Antimatter server is responsible for operating it, for the data it holds, and for the rules that apply to its users.
This website
The content of antimatter.chat is © Antimatter contributors. You may quote and link to it freely. Screenshots show demo data, made up for illustration.
The comparisons with other products reflect their public documentation at the date shown on each page, and may be out of date; names of other products are trademarks of their owners and are used only to identify those products.
Trademarks
Antimatter is based on Mattermost but is not affiliated with or endorsed by Mattermost, Inc. Mattermost is a trademark of Mattermost, Inc. Slack, Rocket.Chat, Discord, Element and Microsoft Teams are trademarks of their respective owners.