Pony (also known as ponylang) is a object-oriented, actor model, capabilities-secure, high performance programming language. Pony's reference capabilities allow even mutable data to be safely passed by reference between actors. Garbage collection is performed concurrently, per-actor, which eliminates the need to pause program execution or "stop the world". Sylvan Clebsch is the original creator of the language. It is now being maintained and developed by members of the Pony team. It is free and open-source software with a BSD 2-clause license.
The language was created by Sylvan Clebsch, while a PhD student at Imperial College London. His professor at that time was Sophia Drossopoulou, who is also well known for her contributions to computer programming, and as a lecturer. According to developers who have talked to Sylvan, he was frustrated with not having a high performance language that could run concurrent code securely, safely, and more simply.
At its core, Pony is a systems language designed around safety and performance.
In Pony, instead of a main function, there is a main actor. The creation of this actor serves as the entry point into a Pony program, as in this "Hello, World!" program.
There are no global variables in Pony, meaning everything must be contained within an instance of a class or an actor. As such, even the environment that allows for printing to standard output is passed as a parameter.