Apple's WebKit team has announced Speedometer 2.0. It’s an update of the benchmarking suite designed to allow browser engineers to test their browser engines.

WebKit is a layout engine software component for rendering web pages in web browsers. It powers Apple's Safari web browser.

In 2014, the WebKit team at Apple released Speedometer 1.0, a benchmark for web app responsiveness. It simulates user interactions in web applications, using TodoMVC to orchestrate adding, completing, and removing todo items. Speedometer repeats these actions using DOM APIs that were extensively used in real-world applications. The performance of these kinds of operations depends on the speed of the JavaScript engine, DOM application programming interfaces, layout, CSS style resolution and other parts of the browser engine.

Browser engineers have been optimizing their engines using Speedometer as a proxy for real-world use of popular frameworks for a number of years. Originally, Speedometer included implementations of todo apps in six popular JavaScript frameworks and libraries in heavy use: Ember, Backbone, AngularJS, jQuery, Flight, and an early version of React. It also included vanilla JavaScript.

Apple says the web developer ecosystem has evolved significantly since Speedometer 1.0 was first released, as have the trends in what libraries, frameworks, and programming paradigms are used. Developers now commonly use transpilers, module bundlers, and recently-introduced frameworks when creating new sites.

For the last year, engineers from WebKit and Chromium have been collaborating on a new version of Speedometer that better reflects the frameworks, tools, and patterns in wide use today. Apple says the Speedometer 2.0 benchmark (http://browserbench.org/Speedometer2.0/) helps browser vendors optimize their browser engines for the modern Web.