The Ecological Impact of Browser Diversity and the Future of Browser Engines

Original author: Rachel Nabors (translated by UC International R&D Jothy)

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Whether you worked at an agency or later at Microsoft Edge, you’ve probably heard the lament: “Why can’t Edge run on Blink? Then I could test all APIs in a single browser!” My view is clear: an Internet that only runs on Chrome’s Blink engine is far from a utopia.

What is a browser? A browser is more than the UI you interact with (bookmarks, address bar, navigation buttons). The UI merely wraps a browser engine , which reads HTML, CSS, and JavaScript from the network, parses them, and renders the page.

Popular engines include Blink (Chrome), WebKit (Safari), Gecko (Firefox), and EdgeHTML (legacy Edge). All engines except EdgeHTML are open‑source, allowing anyone to build a new browser around them. On iOS, the App Store only permits browsers built on WebKit, so Chrome, Firefox, and Edge on iPhone behave like Safari.

Each engine contains two main components:

Layout and rendering engine – calculates page appearance, handles drawing, rendering, and animation.

JavaScript engine – executes JavaScript; examples are Chrome’s V8 and Edge’s Chakra, which can also run on servers (e.g., Node.js).

The author likens a browser engine to a biological cell: the rendering engine is the nucleus (the blueprint), and the JavaScript engine is the mitochondria (power source). Just as cells evolve, browsers evolve.

Browser Evolution

Early browsers were simple; CSS first appeared in IE3 (1996) and JavaScript APIs were sparse. Over decades, engine codebases have grown, adding features that enable modern web experiences.

Today the three dominant engines are:

WebKit/Blink – used by Safari, Chrome, Opera.

Gecko – used by Firefox.

EdgeHTML (a branch of Trident) – used by legacy Microsoft Edge.

Each engine has strengths: Gecko’s multithreaded Servo work, EdgeHTML’s low OS abstraction, Blink’s massive developer base. However, the ecosystem is converging toward Chromium‑based browsers.

Creating a brand‑new engine from scratch is prohibitively costly; even today’s three main engines stem from early web history. Most web traffic now passes through Chrome, iOS Safari, or other Blink/WebKit‑based browsers.

Branching, Refactoring, and Internal Work

Some developers claim WebKit and Blink have diverged too much to share contributions. While they share ancestry, their development paths differ, much like two bird species sharing a class but evolving distinct traits.

EdgeHTML is a branch of Trident (IE’s engine) and retains many of its characteristics, so calling Edge a “complete rewrite” of IE is misleading.

Browser Decline

Only three major rendering engines remain: WebKit/Blink, Gecko, and EdgeHTML. No new lineage is likely to appear soon. Losing any engine would erase its unique heritage and the distinct web capabilities it supports.

Combining Our Strengths

If Microsoft moves Edge to Blink, its engineers could help improve Blink for all Chromium browsers. However, Blink’s fork from WebKit means contributions are not one‑to‑one; differences can lead to fragmented codebases.

Competition Is for Growth, Not Victory

Healthy competition drives better browsers. IE6 once dominated, but its stagnation allowed Firefox to rise, later joined by Chrome, which leveraged a minimalist design, extensive developer tools, and rapid standards adoption to become the de‑facto leader.

Relying on a single engine creates a fragile monoculture; diverse engines provide resilience, innovation, and choice for developers and users alike.

Speculative Biology

The author notes that Microsoft once helped keep Apple alive to preserve OS competition. If only Linux and Windows survived, the personal computing landscape would be very different, and the web would lack the rich variety of APIs and performance characteristics that multiple browsers provide.

Developers must test across multiple browsers, use multiple browsers, and remain both consumers and producers of the web’s future.

Updated: The article now expands on iOS WebKit, Firefox’s role during the IE6 era, and highlights Servo as an exciting development in modern browsers.

Original English article: https://css-tricks.com/the-ecological-impact-of-browser-diversity/

Thank you for reading. The 13th D2 Front‑End Technology Forum will be held on Jan 6, 2019 in Hangzhou. For more front‑end discussions, visit http://d2forum.alibaba-inc.com .