You can use the code from these repositories to experiment, test, build, create patches, issue pull requests, etc.
https://github.com/eclipse/paho.mqtt.c - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.python - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.javascript - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.embedded-c - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.java - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.cpp - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.golang - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt-sn.embedded-c - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.m2mqtt - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.testing - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.android - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.d - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt-spy - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.ruby - Project repository hosted on GitHub.
https://github.com/eclipse/paho.mqtt.rust - Project repository hosted on GitHub.
https://github.com/eclipse/paho.golang - Project repository hosted on GitHub.
https://github.com/eclipse/paho-website - Project repository hosted on GitHub.