The DOM is the foundation of the web platform programming model, and its design and performance impacts the rest of the browser pipeline. However, its history and evolution is far from a simple story.
Over the past three years, we’ve embarked on an in-flight refactoring of the DOM in Microsoft Edge, with our eye on a modernized architecture offering better real-world performance and reduced complexity. In this post, we’ll walk you through the history of the DOM in Internet Explorer and Microsoft Edge, and the impact of our recent work to modernize the DOM Tree, which is already resulting in substantially improved performance in the Windows 10 Creators Update.
What we think of as “the DOM” is really the cooperation of several subsystems. In Microsoft Edge, this includes JS binding, events, editing, spellchecking, HTML attributes, CSSOM, text, and others, all working together. Of these subsystems, the DOM “tree” is at the center.