Khronos API Registry

The Khronos API registry contains specifications, header files, extension specifications, enumerant and function registries, and other related documentation for Khronos APIs.

The Khronos API Implementers Guide, available in HTML and PDF versions, provides guidelines for implementers of OpenGL ES, OpenVG and other API standards specified by the Khronos Group. The aim of these hints is to provide commonality between implementations to ease the logistical problems faced by developers using multiple different implementations of an API. One of the primary goals is to allow an application binary to run on top of multiple different OpenGL ES / OpenVG / EGL implementations on the same platform. Implementers are strongly urged to comply with these guidelines.

The registry is broken down into separate sections for each API. These sections include:

• COLLADA Registry (hosted on collada.org)
• EGL Registry
• OpenCL Registry
• OpenGL Registry (hosted on opengl.org)
• OpenGL ES Registry
• OpenGL SC Registry
• OpenKODE Registry
• OpenMAX AL Registry
• OpenMAX IL Registry
• OpenSL ES Registry
• OpenVG Registry
• OpenWF Registry

Collected Khronos Header Files

Developers wanting to get headers for many Khronos APIs can download them here:

• Khronos header package (Unix compressed tar format)
• Khronos header package (Windows ZIP format)

A summary of the headers in these packages is below, with links to the individual headers from the per-API Registries. Currently the packages include headers for EGL, OpenCL 1.1, OpenGL 4.0, OpenGL ES 1.1, OpenGL ES 2.0, OpenKODE 1.0.3, and OpenVG 1.1.

• Utility header used by multiple API headers
• KHR/khrplatform.h
• EGL Headers
• EGL/eglplatform.h
• EGL/eglext.h
• EGL/egl.h
• OpenCL 1.1 Headers
• CL/cl_gl.h
• CL/cl.h
• CL/cl_gl_ext.h
• CL/opencl.h
• CL/cl_ext.h
• CL/cl_platform.h
• CL/cl_d3d10.h
• OpenGL 4.0 Headers
• GL/gl3.h
• GL/glext.h
• GL/glxext.h
• GL/wglext.h
• OpenGL ES 1.1 Headers
• GLES/glplatform.h
• GLES/glext.h
• GLES/egl.h
• GLES/gl.h
• OpenGL ES 2.0 Headers
• GLES2/gl2.h
• GLES2/gl2ext.h
• GLES2/gl2platform.h
• OpenKODE 1.0.3 Headers
• KD/kd.h
• KD/kdplatform.h
• KD/KHR_thread_storage.h
• KD/KHR_float64.h
• KD/KHR_formatted.h
• KD/KHR_perfcounter.h
• OpenVG 1.1 Headers
• VG/vgu.h
• VG/vgext.h
• VG/openvg.h
• VG/vgplatform.h

Note that if you download individual header files, several of the APIs depend on the shared header file <KHR/khrplatform.h> , which defines common datatypes and calling convention macros.