The Khronos Group - Connecting Software to Silicon

The Khronos Group is a not for profit industry consortium creating open standards for the authoring and acceleration of parallel computing, graphics, dynamic media, computer vision and sensor processing on a wide variety of platforms and devices. All Khronos members are able to contribute to the development of Khronos API specifications, are empowered to vote at various stages before public deployment, and are able to accelerate the delivery of their cutting-edge 3D platforms and applications through early access to specification drafts and conformance tests.

OpenGL - The Industry Standard for High Performance Graphics

OpenGL® is the most widely adopted 2D and 3D graphics API in the industry, bringing thousands of applications to a wide variety of computer platforms. It is window-system and operating-system independent as well as network-transparent. OpenGL enables developers of software for PC, workstation, and supercomputing hardware to create high-performance, visually compelling graphics software applications, in markets such as CAD, content creation, energy, entertainment, game development, manufacturing, medical, and virtual reality. OpenGL exposes all the features of the latest graphics hardware.

OpenCL - The open standard for parallel programming of heterogeneous systems

OpenCL™ is the first open, royalty-free standard for cross-platform, parallel programming of modern processors found in personal computers, servers and handheld/embedded devices. OpenCL (Open Computing Language) greatly improves speed and responsiveness for a wide spectrum of applications in numerous market categories from gaming and entertainment to scientific and medical software.

OpenGL ES - The Standard for Embedded 3D Graphics

OpenGL ES is a royalty-free, cross-platform API for full-function 2D and 3D graphics on embedded systems - including consoles, phones, appliances and vehicles. It consists of well-defined subsets of desktop OpenGL, creating a flexible and powerful low-level interface between software and graphics acceleration. OpenGL ES includes profiles for floating-point and fixed-point systems and the EGL specification for portably binding to native windowing systems. OpenGL ES 1.X: fixed function hardware offering acceleration, image quality and performance. OpenGL ES 2.X: enables full programmable 3D graphics.

EGL - Native Platform Interface

EGL™ is an interface between Khronos rendering APIs such as OpenGL ES or OpenVG and the underlying native platform window system. It handles graphics context management, surface/buffer binding, and rendering synchronization and enables high-performance, accelerated, mixed-mode 2D and 3D rendering using other Khronos APIs.

WebGL - OpenGL ES 2.0 for the Web

WebGL is a royalty-free, cross-platform API that brings OpenGL ES 2.0 to the web as a 3D drawing context within HTML, exposed as low-level Document Object Model interfaces. It uses the OpenGL shading language, GLSL ES, and can be cleanly combined with other web content that is layered on top or underneath the 3D content. It is ideally suited for dynamic 3D web applications in the JavaScript programming language, and will be fully integrated in leading web browsers.

WebCL - Heterogeneous parallel computing in HTML5 web browsers

The WebCL working group is working to define a JavaScript binding to the Khronos OpenCL standard for heterogeneous parallel computing. WebCL will enable web applications to harness GPU and multi-core CPU parallel processing from within a Web browser, enabling significant acceleration of applications such as image and video processing and advanced physics for WebGL games. WebCL is being developed in close cooperation with the Web community and has the potential to extend the capabilities of HTML5 browsers to accelerate computationally intensive and rich visual computing applications.

COLLADA - Digital Asset and FX Exchange Schema

COLLADA™ defines an XML-based schema to make it easy to transport 3D assets between applications - enabling diverse 3D authoring and content processing tools be combined into a production pipeline. The intermediate language provides comprehensive encoding of visual scenes including: geometry, shaders and effects, physics, animation, kinematics, and even multiple version representations of the same asset.COLLADA FX enables leading 3D authoring tools to work effectively together to create shader and effects applications and assets to be authored and packaged using OpenGL® Shading Language, Cg, CgFX, and DirectX® FX

glTF - runtime asset format for WebGL, OpenGL ES, and OpenGL

The "glTF" project aims to define a final stage OpenGL Transmission Format to enable rapid delivery and loading of 3D content by WebGL, OpenGL, and OpenGL ES APIs. glTF together with COLLADA comprise a standards-based content pipeline for rich 3D web and mobile applications. glTF Specification is a work-in-progress from the COLLADA Working Group; it is not an official Khronos-ratified specification yet. It is incomplete and subject to change. The draft specification and related converters and loaders are available on github.

OpenVG - The Standard for Vector Graphics Acceleration

OpenVG™ is a royalty-free, cross-platform API that provides a low-level hardware acceleration interface for vector graphics libraries such as Flash and SVG. OpenVG is targeted primarily at handheld devices that require portable acceleration of high-quality vector graphics for compelling user interfaces and text on small screen devices - while enabling hardware acceleration to provide fluidly interactive performance at very low power levels.

OpenSL ES - The Standard for Embedded Audio Acceleration

OpenSL ES™ is a royalty-free, cross-platform, hardware-accelerated audio API tuned for embedded systems. It provides a standardized, high-performance, low-latency method to access audio functionality for developers of native applications on embedded mobile multimedia devices, enabling straightforward cross-platform deployment of hardware and software audio capabilities, reducing implementation effort, and promoting the market for advanced audio.

OpenMAX IL - The Standard for Media Library Portability

OpenMAX™ is a royalty-free, cross-platform API that provides comprehensive streaming media codec and application portability by enabling accelerated multimedia components to be developed, integrated and programmed across multiple operating systems and silicon platforms. The OpenMAX API will be shipped with processors to enable library and codec implementers to rapidly and effectively make use of the full acceleration potential of new silicon - regardless of the underlying hardware architecture.

OpenMAX AL - The Standard for Media Library Portability

StreamInput - Cross-platform advanced sensor processing and user interaction

The Khronos StreamInput working group is driving industry consensus to create a cross-platform API to enable applications to discover and use new generation sensors to create sophisticated user interactions. The new API will support a general-purpose framework for consistently handling advanced sensors such as depth cameras, touch screens and motion and orientation sensors as well as traditional input devices. StreamInput will provide flexible device discovery to enable an application to select and process high-level semantic input from low-level device capabilities, enabling significant innovations by sensor and device manufacturers while simplifying portable application development. The API will also provide system-wide sensor synchronization for advanced multi-sensor applications such as augmented reality, and will use Khronos’ proven extension mechanisms to enable new types of input devices to be easily added and supported.

OpenVX - Hardware acceleration for Computer Vision applications & libraries

Computer vision has become an essential component of many modern applications including gesture tracking, smart video surveillance, automatic driver assistance, biometrics, computational photography, augmented reality, visual inspection, robotics and more. The OpenVX working group has been formed to drive industry consensus to create a cross-platform API standard to enable hardware vendors to implement and optimize accelerated computer vision algorithms. The OpenVX API can accelerate high-level libraries, such as OpenCV open source vision library, or be used by applications directly. A strong focus will be on providing computer vision on mobile and embedded systems and enabling acceleration on a wide variety of computing architectures including CPUs, GPUs and DSPs. OpenVX will explore interoperability with existing Khronos standards for camera control, video processing, compute acceleration and graphics rendering.

Chapters - Community driven regional meetup groups

Chapters host all kinds of Khronos technology-related events, from casual meet ups and socials to hack fests, fundraisers, guest lectures, community service and educational events.

Other Khronos Group APIs and Technologies

The Khronos Group manages other APIs and Technologies:

OpenGL SC - Safety Critical Profile
OpenMAX DL - The Standard for Media Library Portability
OpenKODE - Khronos Open Development Environment
OpenWF - The Standard for building composited windowing systems
OpenML - The Standard for Dynamic Media Authoring

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Khronos OpenCL API Registry

The OpenCL API registry contains specifications of the core API and a portable intermediate representation of OpenCL programs; specifications of Khronos- and vendor-approved OpenCL extensions; header files corresponding to the specifications; and other related documentation.

OpenCL Core API and SPIR Specification, Headers, and Documentation

The current version of OpenCL is OpenCL 1.2.

OpenCL 1.2 Specification (revision 19, November 14, 2012).
OpenCL 1.2 Extensions Specification (revision 19, November 16, 2012).
OpenCL 1.2 C++ Bindings Specification (revision 9, May 7, 2013).
OpenCL SPIR (Standard Portable Intermediate Representation) (version 1.0 provisional).
OpenCL 1.2 Installable Client Driver (ICD) Loader. The related cl_khr_icd extension allows multiple implementations of OpenCL to co-exist on the same system. The ICD Loader allows applications to choose a platform from the list of installed platforms and dispatches OpenCL API calls to the underlying implementation. Consult LICENSE.txt in the tarball for full terms and conditions.
OpenCL 1.2 Online Manual Pages.
OpenCL 1.2 Reference Card (revision 1111, released November 15, 2011).
All of the following headers should be present in a directory CL/ (or OpenCL/ on MacOS X). The single header file opencl.h includes other headers as appropriate for the target platform, and simply including opencl.h should be all that most applications need to do.
- opencl.h - OpenCL 1.2 Single Header File for Applications.
- cl_platform.h - OpenCL 1.2 Platform-Dependent Macros.
- cl.h - OpenCL 1.2 Core API Header File.
- cl_ext.h - OpenCL 1.2 Extensions Header File.
- cl_dx9_media_sharing.h - OpenCL 1.2 Khronos OpenCL/Direct3D 9 Media Sharing Extensions Header File.
- cl_d3d10.h - OpenCL 1.2 Khronos OpenCL/Direct3D 10 Extensions Header File.
- cl_d3d11.h - OpenCL 1.2 Khronos OpenCL/Direct3D 11 Extensions Header File.
- cl_gl.h - OpenCL 1.2 Khronos OpenCL/OpenGL Extensions Header File.
- cl_gl_ext.h - OpenCL 1.2 Vendor OpenCL/OpenGL Extensions Header File.
- cl.hpp - OpenCL 1.2 C++ Bindings Header File, implementing the C++ Bindings Specification.
- Extension template for writing an OpenCL extension specification. Extensions in the registry (listed below) follow the structure of this document, which describes the purpose of each section in an extension specification.

Older Specifications

Older versions of OpenCL provided for reference.

OpenCL 1.1 Specification (revision 44, June 1, 2011). A Japanese translation of the specification is also available.
OpenCL 1.1 C++ Bindings Specification (revision 4, June 14, 2010).
OpenCL 1.1 Online Manual Pages.
OpenCL 1.1 headers are structured in exactly the same fashion as OpenCL 1.2 headers described above.
- opencl.h - OpenCL 1.1 Single Header File for Applications.
- cl_platform.h - OpenCL 1.1 Platform-Dependent Macros.
- cl.h - OpenCL 1.1 Core API Header File.
- cl_ext.h - OpenCL 1.1 Extensions Header File.
- cl_d3d10.h - OpenCL 1.1 Khronos OpenCL/Direct3D 10 Extensions Header File.
- cl_gl.h - OpenCL 1.1 Khronos OpenCL/OpenGL Extensions Header File.
- cl_gl_ext.h - OpenCL 1.1 Vendor OpenCL/OpenGL Extensions Header File.
- cl.hpp - OpenCL 1.1 C++ Bindings Header File, implementing the C++ Bindings Specification.

OpenCL 1.0 Specification (revision 48, October 6, 2009).
OpenCL 1.0 Online Manual Pages.
OpenCL 1.0 headers are structured in exactly the same fashion as OpenCL 1.2 headers described above.
- opencl.h - OpenCL 1.0 Single Header File for Applications.
- cl_platform.h - OpenCL 1.0 Platform-Dependent Macros.
- cl.h - OpenCL 1.0 Core API Header File.
- cl_ext.h - OpenCL 1.0 Extensions Header File.
- cl_d3d10.h - OpenCL 1.0 Khronos OpenCL/Direct3D 10 Extensions Header File.
- cl_gl.h - OpenCL 1.0 Khronos OpenCL/OpenGL Extensions Header File.
- cl_gl_ext.h - OpenCL 1.0 Vendor OpenCL/OpenGL Extensions Header File.
- cl.hpp - OpenCL 1.1 C++ Bindings Header File, implementing the C++ Bindings Specification. This header works for OpenCL 1.0 as well as OpenCL 1.1.

Providing Feedback on the Registry

Khronos welcomes comments and bug reports. To provide feedback, please create an account on the Khronos Bugzilla and file a bug. Make sure to fill in the "Product" field in the bug entry form as "OpenCL" and pick appropriate values for the other fields.

If you are already logged into Bugzilla, the following links will prepopulate the bug report fields as appropriate for:

feedback on the OpenCL Header Files and (NOTE: you must be logged into Bugzilla before clicking on this link)
feedback on the OpenCL C++ Bindings (NOTE: you must be logged into Bugzilla before clicking on this link)

You can also post feedback to the OpenCL Message Board in a new thread, or there is an existing thread specifically created to discuss the OpenCL C++ Bindings .

The Khronos Group - a non-profit industry consortium to develop, publish and promote open standard, royalty-free media authoring and acceleration standards for desktop and handheld devices, combined with conformance qualification programs for platform and device interoperability.

Connecting Software to Silicon

The Khronos Group - Connecting Software to Silicon

OpenGL - The Industry Standard for High Performance Graphics

OpenCL - The open standard for parallel programming of heterogeneous systems

OpenGL ES - The Standard for Embedded 3D Graphics

EGL - Native Platform Interface

WebGL - OpenGL ES 2.0 for the Web

WebCL - Heterogeneous parallel computing in HTML5 web browsers

COLLADA - Digital Asset and FX Exchange Schema

glTF - runtime asset format for WebGL, OpenGL ES, and OpenGL

OpenVG - The Standard for Vector Graphics Acceleration

OpenSL ES - The Standard for Embedded Audio Acceleration

OpenMAX IL - The Standard for Media Library Portability

OpenMAX AL - The Standard for Media Library Portability

StreamInput - Cross-platform advanced sensor processing and user interaction

OpenVX - Hardware acceleration for Computer Vision applications & libraries

Chapters - Community driven regional meetup groups

Other Khronos Group APIs and Technologies

Quick Links:

Khronos OpenCL API Registry

Khronos OpenCL API Registry

OpenCL Core API and SPIR Specification, Headers, and Documentation

Older Specifications

Providing Feedback on the Registry

Extension Specifications