Bez: Generating a browser engine from specs and tests

A web engine can now be generated automatically, reducing the need for large engineering teams to build one.

Bez, an open-source project by burrito.space, aims to generate a web rendering engine from specifications and tests. Unlike traditional browser engines built by large engineering teams over many years, Bez automates this process. It takes web standards as input and uses them to generate code that is then tested against the behavior of Chromium, Firefox, and WebKit. The project also incorporates Web Platform Tests (WPT) for verification. The goal is to create a complete, tree-shaken, and embeddable engine that can be updated rapidly as web standards evolve. Currently, a small percentage of CSS layout rules have been generated, with the majority of the engine's core components like DOM and style trees still being hand-written, though they pass cross-browser checks.

Bez's approach to generating a browser engine from specs and tests signifies a potential shift in how core web technologies are developed. By automating the creation of rendering engines, it lowers the barrier to entry for creating custom browser components or analyzing web standards in depth. This method could lead to more diverse implementations and specialized engines tailored for specific applications, rather than relying solely on the monolithic engines from major browser vendors.

The project's current status, with a small but growing percentage of generated CSS rules, indicates the feasibility of this automated generation. As more rules and features are incorporated, Bez could offer a more cost-effective and agile alternative for developers needing browser engine capabilities. The continuous integration against multiple browsers and WPT ensures a high degree of compatibility and adherence to standards, which will be crucial for its adoption.