The Lightweight Java Game Library (LWJGL) provides access to high performance, cross-platform libraries OpenGL, OpenCL and OpenAL. Additionally LWJGL provides access to controllers such as Gamepads, Steering wheel and Joysticks.
LWJGL is not meant to make writing games particularly easy; it is primarily an enabling technology which allows developers to get at resources that are simply otherwise unavailable or poorly implemented on the existing Java platform.
LWJGL is available under a BSD license, which means it's open source and freely available at no charge.
LWJGL version 3 is a complete rewrite of LWJGL, which removed some functionality in favor of new API bindings like GLFW.