Igalia's Role in Chromium: CSS Grid, MathML, and Wayland

Open-source consultancy Igalia has quietly become one of the most influential contributors to the Chromium web browser, consistently ranking just behind Google in total code commits. By stepping in to build complex features that major browser vendors often deprioritize, the worker-owned cooperative has significantly advanced both the open web and the Linux ecosystem. This article provides a direct look at how Igalia engineered and implemented three foundational technologies in Chromium: CSS Grid Layout, native MathML rendering, and native Wayland integration for Linux.

Revolutionizing Web Design with CSS Grid

Before 2017, web developers relied on fragile workarounds like floats, positioning, and flexbox to create complex two-dimensional page layouts. While the W3C had a specification for CSS Grid, browser vendors were hesitant to invest the massive engineering resources required to build it.

Igalia stepped in to bridge this gap. Funded largely by Bloomberg, which needed advanced layout capabilities for its financial web applications, Igalia began implementing CSS Grid in Chromium's Blink engine (as well as Apple's WebKit) in 2013. Over four years, Igalia's engineers did the heavy lifting:

  • Code Implementation: They wrote the core layout algorithms in Blink to interpret and render grid properties.
  • Specification Refinement: Working closely with the W3C CSS Working Group, Igalia provided real-world implementation feedback to finalize the CSS Grid specification.
  • Cross-Browser Interoperability: By writing the code for both Chromium and WebKit, and collaborating with Mozilla, Igalia ensured that CSS Grid behaved identically across all major browsers.

Thanks to Igalia, CSS Grid launched simultaneously in Chrome, Firefox, and Safari in March 2017, fundamentally changing how websites are built.

Bringing Native MathML Back to Chromium

MathML (Mathematical Markup Language) is the web standard for displaying complex mathematical equations natively in HTML. In 2013, Google removed an older, incomplete version of MathML from Chromium due to security vulnerabilities, slow performance, and a lack of maintainers. This forced developers to rely on heavy JavaScript libraries or static images to render math on the web.

Determined to make math a first-class citizen of the web again, Igalia launched an initiative in 2019 to re-implement the standard from scratch. Rather than using the bloated legacy specification, Igalia helped draft "MathML Core," a streamlined version designed specifically for modern browser engines.

Igalia’s implementation strategy focused on three key areas:

  • LayoutNG Integration: They built MathML directly on top of Chromium's modern layout engine, LayoutNG, ensuring high performance and rock-solid stability.
  • Security: By leveraging existing text and layout primitives within Chromium rather than writing isolated code, they eliminated the security risks that plagued the 2013 version.
  • Accessibility and Styling: They ensured the new implementation worked seamlessly with screen readers and modern CSS properties.

After years of rigorous testing and upstream code reviews, Igalia’s implementation was officially enabled by default in Chromium 109 in January 2023.

Modernizing Linux with Native Wayland Support

For decades, Linux desktops relied on the aging X11 windowing system. As the Linux community began transitioning to Wayland—a modern, secure replacement for X11—Chromium lagged behind. On Wayland systems, Chromium had to run through a compatibility layer called XWayland, which resulted in blurry text on high-DPI screens, broken touchpad gestures, and poor graphics performance.

While Google focused on ChromeOS, Igalia took on the monumental task of bringing native desktop Wayland support to Chromium for standard Linux distributions and embedded systems (such as automotive displays).

Igalia achieved this by overhauling Ozone, Chromium's platform abstraction layer used for graphics and input event handling. Their contributions included:

  • The Ozone-Wayland Backend: Igalia wrote the backend code that allows Chromium to communicate directly with Wayland compositors without needing X11.
  • X11 Deprecation Prep: They untangled legacy X11-specific code from the main Linux build of Chromium, unifying the architecture under Ozone.
  • Feature Parity: Igalia resolved complex issues specific to Wayland, including drag-and-drop functionality, clipboard sharing, fractional scaling, and hardware-accelerated video decoding.

Because of Igalia's sustained engineering efforts, Chromium now runs natively on Wayland, offering Linux users a vastly superior, smoother, and more secure browsing experience.