BrowserEngines

Browser engines, also called rendering engines, are software components inside web browsers responsible for displaying web content. They parse HTML, CSS, and images, construct a document model, compute styles, perform layout, and paint pixels to the screen. They also work with the browser's JavaScript engine and expose APIs for user interface rendering.

Most browsers pair a rendering engine with a separate JavaScript engine. Examples: Google Chrome and Microsoft Edge use Blink as their rendering engine and V8 as the JavaScript engine. Safari uses WebKit as the rendering engine and JavaScriptCore as the JavaScript engine. Mozilla Firefox uses Gecko as the rendering engine and SpiderMonkey as the JavaScript engine.

History and landscape: WebKit originated from KHTML; Blink is a fork of WebKit created by Google in 2013. Edge transitioned from EdgeHTML to Blink in 2020 to align with Chromium. Firefox uses Gecko, independent from Blink/WebKit. Other historical engines include Trident (Internet Explorer) and EdgeHTML (older Edge). The contemporary browser market is largely dominated by a small set of engines, each with distinct development and release cycles.

Impact and considerations: Engine choices influence performance, security isolation, and feature support. Standards compliance helps ensure cross-browser compatibility, but differences in engine implementations can require testing and the use of polyfills or shims. Engines receive frequent updates to implement web standards, optimize performance, and address security concerns, shaping how developers write and test web applications.