Psi

Psi is a free, open‑source instant messaging client built for the XMPP network. It runs on Windows, Linux and macOS, offering a consistent experience across desktop platforms. The application follows XMPP standards, allowing users to connect to any XMPP server without proprietary extensions.

The client provides full Unicode support, enabling communication in a wide range of languages and scripts. File transfers are handled directly within the chat window, and users can personalize the interface with custom icon sets and other visual tweaks. Localization files are included, so the program can be used in multiple languages out of the box.

Designed to be lightweight and responsive, Psi aims to deliver a straightforward messaging experience while remaining fully open source. Its stable release status indicates that core functionality is reliable for everyday use, and the project continues to receive updates and community contributions.