The most scalable open-source MQTT broker for IoT, IIoT, and connected vehicles

Erlang/OTP

Robust, Ubiquitous and Massively Scalable Messaging Platform (XMPP, MQTT, SIP Server)

Haskell-style functional programming language running on Erlang VM.

The core of an open-source, distributed, highly scalable platform designed to provide robust telecom services

A simple, pure erlang, raspberry pi user-space gpio library