Khronos Intellectual Property Framework Briefing

Khronos Background

Khronos is an industry consortium created “by the industry for the industry” to enable safe cooperation for the creation of royalty-free open API standards for graphics, media, compute, vision and sensor acceleration. Khronos has over 100 Member companies, is commercially focused on growing hardware and software market opportunities, and manages specifications such as OpenGL®, OpenGL® ES, WebGL™, WebCL™, OpenCL™, OpenMAX™, OpenSL ES™, OpenVG™, StreamInput™ and COLLADA™. More details about current Khronos Members and specifications can be found on the Khronos website at

Khronos’ primary products are open specifications and associated conformance tests that enable hardware and software communities to effectively communicate with each other. ‘Open’ does not primarily mean open source implementations of those specifications, though Khronos does often encourage and support open source projects where useful and appropriate. Rather, Khronos specifications are “open” in four senses:

  1. any company is invited and able to join Khronos to contribute to and influence the development of Khronos specifications;
  2. finalized specifications are publicly and freely distributed at zero cost from the Khronos web-site;
  3. implementers have to pay zero royalties to Khronos members for technology in the specifications; and
  4. developers may freely use implementations of Khronos specifications.

The most critical aspect of any collaborative creation of API standards is the Intellectual Property Rights (IP) Framework under which that collaboration occurs. An effective IP Framework balances two goals:

  1. providing protection for bona fide implementers so that Khronos members will not assert IP rights or demand royalties against a company for implementing a Khronos specification;
  2. minimizing the licensing obligations of each member company to protect members’ IP properties. Khronos has a carefully constructed IP Framework that is explained in more detail below.

While Khronos specifications are under construction, drafts and other detailed materials are confidential to the Khronos membership. This is to protect the specifications by preventing non-Khronos members mining drafts for potential patent applications before standards are finalized and released. Sounds paranoid – but it really does happen!

Khronos members sign a membership agreement that brings them under the cooperative IP Framework, they agree to keep Khronos draft materials confidential, and they execute a conformance test source license that enables them to particpate in creating and reviewing a body of code used to test implementations for compliance with Khronos specifications. There is a $10K corporate annual membership fee to fund Khronos’ activities and which includes access to any or all of the Khronos working groups with voting rights. Accredited academic institutions may join Khronos for just $1K per year which enables non-voting participation in all Khronos working groups.

Khronos IP Framework

Understanding the IP framework is one of the most important steps in deciding whether any collaborative project makes sense for your company or institution. Everyone should, of course, take care not to not enter into agreements where their IP is “given away” or licensing control over their IP is diluted.

Khronos has a state-of-the-art IP framework that provides meaningful protection to Khronos specifications while also providing strong protection for members IP. This has enabled many companies with significant IP portfolios to enjoy Khronos membership benefits as they are complemented with tightly defined and restricted IP licensing obligations.

The Khronos IP policy can be summarized in that all Khronos members reciprocally agree not to assert IP rights for technology in a Khronos specification against any other Khronos member that is implementing that specification. As Khronos membership is available to any company at a nominal price, this effectively means that any company interested to implement a Khronos specification can execute the royalty-free reciprocal license.

Protection of Khronos Member IP

The Khronos IP framework provides multiple mechanisms by which the IP of members is protected as default – plus there are additional elective protective measures members can choose to use.

To maximize protection for member IP the reciprocal license grant is carefully minimized and does NOT cover:

  1. implementations that are not fully conformant, as defined by passing Khronos conformance tests;
  2. IP that is not essential, i.e. where any commercially viable alternative implementation techniques exist that do not need a member’s IP to be licensed; and
  3. any technology that is not explicitly called out in the specification for interoperability, meaning that underlying hardware or software implementation techniques are not licensed through Khronos participation.

This very narrow licensing scope often means that in practice members are licensing very little, if any, IP. Plus, as the license grant is reciprocal between all Khronos members, in return for their grant each member receives royalty-free licenses for essential IP in Khronos specifications from all other participating Khronos members.

The Khronos IP Framework is designed to make licensing obligations precisely understandable: a) the only point of licensing is the instant of ratification by the Khronos Board, and ONLY essential IP in the final spec is reciprocally licensed, meaning that discussions and contributions not included in the final specification bring no licensing obligation; b) Khronos members do not have to disclose any IP that will be included under the standard reciprocal license – so no patents are ever discussed in open Khronos meetings so that members are not put on notice of specific patents.

As Khronos activities span a wide range of APIs, Khronos members can explicitly withdraw from participation in any subset of working groups by issuing a Working Group Exclusion Certificate. If a Working Group Exclusion Certificate is in place, and the member does not attend any meetings for the excluded working group, the member does not particpate in any way in the reciprocal licensing grant for specifications produced by that working group.

If members have specific patents they do not want to be included in the reciprocal license, they can issue an “IP Disclosure Certificate” prior to Ratification to exclude specific essential claims from the reciprocal license, regardless of whether or not those claims are associated with an explicit contribution from the participant. This means if your company has essential patents that you do not wish to license, those patents can always be ring-fenced. In practice, due to the narrowness of the reciprocal license, Members only rarely find it necessary to exclude a specific patent; in fact this mechanism has only been invoked a handful of times in the ten year history of Khronos Group.

Finally, before any specification is ratified, there is a Ratification Review Period of at least 45 days and all members are notified of the start of the Review Period. IP Disclosure Certificates can be issued at any time during drafting, not just during the Review Period, but the notifications provide a reminder to all members that ratifications are scheduled in case they wish to take any elective actions.

October 2012

View IP Disclosure Certificates PDF Version of IP Framework

Company Date API Patents Letter
SGI 2005-03-01 OpenGL US #6650327 View Letter
Ericsson 2005-07-22 OpenGL ES REG SE 0303497-2
View Letter
Apple 2006-06-19 OpenGL US #5404447 View Letter
Creative 2006-07-14 OpenSL ES US#6917686 View Letter
S3 2007-12-12 OpenGL US #5956431, #6683978 View Letter
Apple 2009-08-01 OpenWF US5,276,531
View Letter
Matrox Graphics Inc 2010-03-01 OpenGL US #6940505 View Letter
NVIDIA 2010-06-21 OpenGL US #5651104 View Letter
Apple 2011-02-02 WebGL US #5,404,447 View Letter
S3 Graphics 2011-11-01 OpenGL US #5,956,431
US #6,236,405
US #6,937,250
US #6,658,146
US #6,683,978
US #6,775,417
US #7,039,244
US #7,043,087
EP 1,034,505 B1
US #7,801,363

View Letter