Eclipse Golo is a dynamically-typed programming language for the Java Virtual Machine. Golo is largely interoperable with Java and other JVM languages (e.g., numeric types are boxing classes from java.lang, and collection literals leverage java.util classes). Golo supports imperative and functional programming patterns. Golo is not a strictly object-oriented programming language: it very much resembles Go in the sense that methods are just functions applied to specific receiver types. Golo or Java defined types can be augmented in Golo, that is, new methods can be made available.
Eclipse Californium (Cf) is an open source implementation of the Constrained Application Protocol (CoAP). It is written in Java and targets unconstrained environments such as back-end service infrastructures (e.g., proxies, resource directories, or cloud services) and less constrained environments such as embedded devices running Linux (e.g., smart home/factory controllers or cellular gateways).
Eclipse Mosquitto provides a lightweight server implementation of the MQTT protocol that is suitable for all situations from full power machines to embedded and low power machines. Sensors and actuators, which are often the sources and destinations of MQTT messages, can be very small and lacking in power. This also applies to the embedded machines to which they are connected, which is where Mosquitto could be run.