Test262 is a conformance test suite for ECMAScript, the programming language on which JavaScript is based. Containing 36,103 individual tests at the time of this writing, Test262 ensures that different implementations of the language, such as the JavaScript engines in web browsers or stand-alone runtimes like Node.js or Moddable XS, agree on the minutiae of […]

Last year we formed a team focused on using the growing number of new web APIs to build multimedia applications that push the edge of the web platform. Our main work in this area over the last 2 years has been with the wonderful team behind Scratch at MIT’s Lifelong Kindergarten Group (LLK), and with […]


Bocoup has been a long-time contributor to the Web Platform Tests (WPT) project, helping spec writers draft testable specs and helping browser implementers test features for correctness and interoperability based on those specs. In 2018, we’ve made great strides improving the coverage of WPT, the ergonomics of writing and running tests, and the infrastructure necessary […]


The web-platform-tests project (WPT) houses over a million tests written to ensure our browsers provide a consistent experience of the web. WPT predates most of today’s popular JavaScript testing frameworks, so it implements one of its own: testharness.js. In December of 2017, I offered to extend testharness.js with a new feature. No one expected this […]


Today we’re launching Test262 Report to provide JavaScript developers with up-to-date information on the state of new and existing language features across implementations. Test262 Report is based on daily runs of Test262, the ECMA-262 (“ECMAScript” or “JavaScript”) test suite, in nightly builds of JavaScript engines, and visualizes at-a-glance status of feature implementation progress. Taking a […]

Bocoup recently facilitated an update to the WebKit project’s interaction with Test262. In this article, I’ll cover what this means for the WebKit project and the JavaScript ecosystem, as well as what exactly has been done in the WebKit project to help make this process more repeatable. Test262 is a project maintained by Ecma’s TC39. […]

We recently started working with browser implementers to improve the state of fieldset, the 21 year old feature in HTML, that provides form accessibility benefits to assistive technologies like screen readers. It suffers from a number of interoperability bugs that make it difficult for web developers to use. Here is an example form grouped with […]

On June 13, operations screeched to a halt here at Bocoup. The phones were ringing, but we didn’t answer them. Packages delivered to our door went ignored. Chicken eggs piled up. All hands were on keyboards, collaborating on the web-platform-tests project. We’ve been participating in WPT for years, largely in collaboration with the Chromium, Gecko […]


I’m excited to share that our technical partnerships team has developed a deeper focus on graphics and interactive application programming, a focus area which we are affectionately calling Gaia. As of today, Technical Partnerships is now Graphics and Interactive Applications (Gaia for short). In many ways this is a reflection of what this team has […]

Software development is a costly process. Requirements need to be gathered, decisions need to be made, and resources need to be scheduled to write the software. All of these steps require an investment of time and money to get a feature to the point where it starts bringing value to a business. After the feature […]