A browser-engine is a core software component that renders web content by transforming HTML documents and other resources into an interactive visual representation. It acts as the intermediary between the network layer and the user interface, orchestrating the document-object-model and cssom to produce a rendered page. According to MDN Web Docs, the engine is responsible for layout, painting, and enforcing security policies like the same-origin-policy.
Key Modern Engines
The web landscape is currently defined by three primary engines. Blink is the most widely used engine, developed as part of the chromium project by google and other contributors. It powers google-chrome, microsoft-edge, and opera. WebKit, originally derived from khtml, is maintained by apple and serves as the engine for safari. Lastly, Gecko is the engine developed by the mozilla-foundation for the firefox browser. Detailed information on engine development can be found at WebKit.org and the Blink Project.
Relationship with Scripting
While the browser-engine handles the visual structure, it relies on a javascript-engine to execute code. For instance, Blink uses the v8 engine, while Gecko utilizes spidermonkey. This integration is crucial for dynamic-web-pages and web-applications. Historical engines like trident and edgehtml have largely been deprecated as the industry moves toward unified web-standards.