Cocos2d is an open-source game development framework that allows developers to create 2D games and interactive applications. It provides a rich set of features, including graphics rendering, physics simulation, and sound management, making it easier to build engaging experiences for various platforms, such as mobile devices and desktops. Originally developed in Python, Cocos2d has since evolved into several versions, including Cocos2d-x, which is written in C++ and supports multiple programming languages. The framework is popular among indie developers due to its flexibility, ease of use, and strong community support, enabling users to share resources and collaborate on projects.