jMonkeyEngine is an open-source 3D game engine written in Java, designed for cross-platform development. It supports advanced rendering, physics (via Bullet), and animations, ideal for 3D games or simulations. jMonkeyEngine targets Windows, macOS, Linux, Android, and iOS, with a scene graph for efficient rendering. Its visual editor and SDK simplify workflows, appealing to Java developers. The community provides tutorials and forums, though smaller than Unity’s. jMonkeyEngine’s BSD license ensures no royalties, and its Java foundation offers portability. While 2D support is limited, it excels in 3D projects like educational tools or indie games. Actively maintained, it’s perfect for developers comfortable with Java seeking a robust, lightweight 3D engine.