Pony (programming language)

Pony is an open-source, object-oriented, actor-model, capabilities-secure programming language. It is designed for high-performance, concurrent, and distributed applications. Pony emphasizes safety, both in terms of memory management and data races.

Pony's core features revolve around its type system, which uses capabilities to manage object access and concurrency. Capabilities in Pony define not only the type of an object but also how that object can be accessed and modified. This approach allows the compiler to enforce strong guarantees about data races and memory safety at compile time, reducing the risk of runtime errors and improving application reliability.

The actor model is central to Pony's concurrency design. Actors are independent, isolated entities that communicate with each other through asynchronous message passing. This model inherently avoids shared mutable state, further simplifying concurrent programming and reducing the likelihood of data races. Pony's actor system is designed to be lightweight and efficient, enabling the creation of applications with a large number of concurrent actors.

Automatic memory management in Pony is achieved through a technique called epoch-based garbage collection. This approach divides memory into epochs, and actors are associated with a particular epoch. Garbage collection is performed on a per-epoch basis, minimizing pauses and improving overall performance.

Pony aims to provide a balance between high performance, strong safety guarantees, and a relatively simple programming model, making it suitable for a wide range of concurrent and distributed applications where reliability and performance are critical. Its focus on capability-based security also makes it well-suited for developing secure systems.