Quaternion is a cross-platform Qt5-based desktop IM client for Matrix.
Quaternion is packaged for many distributions, including various versions of Debian, Ubuntu and OpenSUSE, as well as Arch Linux, NixOS and FreeBSD
This is free and open source software.
Key Features
- Room tag showing.
- Room tag editing.
- Room user list.
- Display room description.
- Edit room description.
- Highlights.
- Send read markers.
- Sending invites.
- Accepting invites.
- Typing notification.
- Attachment uploading and downloading.
- Display formatted messages.
- Redacting.
- Room upgrades.
- SSO support.
- Cross-platform support – runs under Linux, macOS, and Windows.
Website: github.com/quotient-im/Quaternion
Support:
Developer: Alexey Rusakov and contributors
License: GNU General Public License v3.0

Quaternion is written in C++. Learn C++ with our recommended free books and free tutorials.
Related Software
| Matrix Clients | |
|---|---|
| Fractal | Matrix client for GNOME |
| NeoChat | Fork of Spectral |
| Cinny | Focuses primarily on a simple, elegant and secure interface |
| nheko | Desktop client using Qt and C++ |
| Element | Glossy client with an emphasis on performance and usability |
| FluffyChat | Multi-platform Matrix client with a simple and clean user interface |
| Quaternion | Qt5-based IM client |
| Commet | Feature rich experience while maintaining a simple interface |
| Moment | Fancy, customizable, keyboard-operable Matrix chat client |
| SchildiChat | Matrix client / Element Web/Desktop fork |
| Sable | Polished messaging app with a strong focus on everyday usability |
| Hydrogen | Minimal Matrix chat client |
| Extera | Feature-rich chat app derived from FluffyChat with a fresh approach |
| Tammy | Privacy-minded messenger with secure conversations and clean design |
| Syphon | Privacy centric Matrix client |
| Chatty | Unified messaging app designed for desktop and mobile devices |
| Chats | Messaging application for mobile and desktop |
| Quadrix | Minimal, simple, multi-platform chat client |
| Matrix | Modern chat app with rooms, accounts, media and encryption |
| Spectral | Glossy native client designed with simplicity in mind |
| Mirage | Fancy, customizable, keyboard-operable Matrix chat client |
| kazv | Convergent Matrix client and secure messaging app |
Read our verdict in the software roundup.
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