Gymnasium

Gymnasium is a maintained, open-source Python library and API standard for reinforcement learning (RL) that provides a unified interface for interacting with a large collection of RL environments. Building on the legacy of OpenAI's Gym, it is designed for researchers, developers, and educators working on RL algorithms and experimentation, offering both classic and modern environments. The framework emphasizes simplicity, compatibility, and extensibility, making it a core tool for RL research and practical RL applications.