**PettingZoo** is an open-source Python library for **multi-agent reinforcement learning (MARL)** environments. It provides standardized interfaces for creating, running, and comparing multi-agent simulations, making it easier for researchers and developers to build and evaluate MARL algorithms.

Features of PettingZoo:

• Provides a consistent API for a wide variety of multi-agent environments, similar to OpenAI Gym.
• Supports multiple environment families, including classical games, particle simulations, and Atari games.
• Facilitates reproducible research and easy benchmarking of MARL algorithms.
• Integrates seamlessly with popular RL libraries like **RLlib**, **Stable Baselines3**, and **TorchRL**.
• Compatible with both single-machine and distributed training setups.
• Open-source and actively maintained, widely used in research and educational projects.

To check the installed version of PettingZoo on Ubuntu 24.04, run these commands in your environment:

$ sudo su
$ sudo apt update
$ source ~/pettingzoo-venv/bin/activate
$ pip show pettingzoo

Disclaimer: PettingZoo is released under the MIT License and maintained by the PettingZoo community. Users are responsible for correct usage in their specific applications. Always refer to the official PettingZoo documentation for the most accurate and up-to-date information.