Any company may freely use the publicly released WebGL specification to create a product, but implementations of the WebGL specification must be tested for conformance in the Khronos WebGL Adopters program before the WebGL name or logo may be used in association with an implementation of the specification.
Implementers may join the WebGL Adopters Program which enables them to download and execute the WebGL conformance tests and upload the results for peer review within Khronos. If the implementation successfully passes the tests, the Adopter is granted a royalty-free trademark license to use the WebGL name and logo in association with that implementation - and they can refer to the implementation as being WebGL conformant or WebGL compliant. There is no fee to become a WebGL adopter. More details on becoming a WebGL Adopter may be found on the Khronos Adopters page, and on the WebGL Conformance Rules page.
The WebGL Conformance Test Suite, along with instructions, is availble on Github.
If you have questions about becoming a WebGL Adopter, please send an email to memberservices at khronos.org
WebGL and the WebGL logo are trademarks of the Khronos Group Inc. The WebGL logo and guidelines for its usage in association with Conformant products.