Mumble

Mumble provides real‑time voice and text communication with low latency and high audio quality, built on Qt and the Opus codec. It consists of a client application and a separate server component (formerly murmur), allowing users to host their own voice‑chat infrastructure. The client runs on Windows, Linux, FreeBSD, OpenBSD and macOS, while the server can be deployed on any platform that supports Qt.

The project is released under the BSD‑3‑Clause license, offering a self‑hostable, free‑tier solution without subscription requirements. Source code is openly available, and the community supplies documentation, translation support via Weblate, and a plugin system for extending functionality beyond the core features.

Mumble is positioned for groups that need reliable, low‑delay voice chat—such as gamers, remote teams, or any collaborative environment—while giving administrators full control over the server configuration and the ability to contribute code or translations through its open development workflow.