XMQ — a fast, free MQTT server for Linux and Windows

XMQ is a cross-platform MQTT server written in C++. It implements MQTT protocol versions 3.1, 3.1.1, and 5.0 with QoS levels 0, 1, and 2, TLS encryption, message persistence over database backend, and MQTT bridging between nodes. A single instance serves up to 1 million concurrent clients.

Runs as a Linux MQTT server (.deb and .rpm packages) and as a Windows MQTT server.
Acts as an MQTT bridge, forwarding messages between XMQ nodes and other MQTT servers.
Ships with an open MQTT test suite built on standard MQTT protocols, so the published MQTT performance tests can be reproduced and compared against other MQTT servers.

XMQ is free, released under the GPL/LGPL License Agreement v2.0 that can be found here, and is distributed as binary packages from the Downloads page.

Built with SPTK

XMQ is built on top of SPTK (Simply Powerful Toolkit), the cross-platform C++20 class library developed alongside it. SPTK provides the networking, threading, database and XML/JSON layers that XMQ runs on, and is available separately in source code and binary packages from the Downloads page.

Release history

Below is the history of development for the last 12 months, a kind of changelog and new version announcements.



Credits:	The XMQ web site is provided by Linotex.	The XMQ and SPTK Windows installers are created with Advanced Installer free Open-Source license.