A photo of my face against a blue background.I'm Patrick, a product manager on the Edge team at Microsoft. I do developer relations, and work on a wide range of web platform technologies and tools. Previously, I worked at Mozilla, on the Firefox DevTools team.
I'm part of the Open Web Docs governing committee and a co-chair of the W3C WebDX community group. I also run DevTools Tips.

I have 20+ years of working experience with the web and have worked as a designer, web developer, software engineer, browser engineer, engineering manager, and product manager.

To get in touch, use the links to my social networks at the bottom of this page, or email me: patrickbrosset at gmail dot com.

Calling for Interop 2026 proposals

You can now create Interop 2026 proposals! Interop has been running for 5 years, and is an important tool for companies building browser engines to improve the state of interoperability on the web. Something we know developers care about the most. Help us find the areas to focus on next year.

The interoperability graph on the Interop 25 dashboard. For illustration only.

AI agents and the web - A proposal to keep developers in the loop

WebMCP is an early proposal that allows web developers to take control of how AI agents use their web pages on behalf of users. In this post, I'm providing a short introduction of the proposal, together with a demo. I'm also calling for feedback! If this sounds interesting, please read on and let me know what you think.

A hand-drawn diagram of the WebMCP proposal, showing a user interacting with a webpage in a browser. The user interacts with the page in two ways. One way is directly, as normal, using the browser UI. The other way is through an an AI agent which communicates with the page by using an embedded MCP server in the browser.

Brick by brick: Help us build CSS Masonry

We're working on implementing CSS Masonry in Chromium and are super excited to announce that it's now ready for developer trial. In this blog post, you'll learn about the syntax that's available for you to try, and get inspired by a bunch of examples.

A CSS Masonry layout example, showing a photo gallery where the title spans multiple columns.

CSS gap decoration resources

A list of all the resources you will need to learn more about the CSS gap decoration proposal, to try it out in your own projects, and provide feedback.

A grid layout illustration with blue column decorations and red row decorations.

CSS alignment in block layouts

Testing the align-* and justify-* CSS properties in a block layout. View the source code of that page to learn more.

A blue square inside a gray square

web-features and Baseline (AC 2025)

A short talk at the W3C AC meeting in April 2025, to update the AC on the web-features project and Baseline. Video, slides.

W3C AC 2025 logo.

web-features and Baseline - We're feature complete! What's next? (W3C Breakouts Day)

The WebDX Community Group has done a lot of work in 2024 to increase the coverage of its web-features data. Now that the data roughly covers the entire web platform feature set, let's review the work done so far, the use cases that web-features, and Baseline, have unlocked, and let's open it up for discussion on the next important questions to tackle.
Slides

W3C Breakouts Day 2025 logo.