The W3C TAG Meeting in London, March 2026

Earlier this month, the W3C Technical Architecture Group (TAG) gathered in London for a multi-day face-to-face meeting. While the TAG meets regularly online, these in-person sessions remain an important part of how the group builds shared understanding, tackles complex architectural questions, and welcomes new members into the work.

The TAG plays a unique role in the W3C ecosystem. As the group responsible for the architectural integrity of the Web, the group reviews emerging technologies, produces design principles and findings, and helps ensure that new work aligns with the long-term health of the platform. In practical terms, that means asking questions like:

• Does a new web feature fit the existing architecture?  
• Does it respect core web principles such as user choice, privacy, and interoperability?  
• What unintended consequences might appear as the technology scales?

Welcoming new TAG members

The London meeting also marked the first face-to-face gathering for several new TAG participants. The group welcomed Brian Kardell, Christian Liebel, Yu Sen, and me who joined the TAG this year.

As part of the introductions, members reflected on how the TAG has evolved over time. Several noted that while the TAG once felt distant or opaque from the outside, the group today aims to be much more connected to the day-to-day realities of building the Web and reviewing real implementations.

That perspective continues to shape the TAG’s approach: grounding architectural thinking in real-world deployment while still keeping an eye on the long-term direction of the Web.

At the same time, the TAG expressed its appreciation to outgoing members Martin Thomson and Dapeng Liu for their service and contributions to the group’s work and the broader Web community.

Why face-to-face meetings still matter

The TAG is a geographically distributed group spanning multiple time zones, which means most collaboration happens asynchronously or in short online meetings. While this works well for many tasks, some discussions benefit from dedicated in-person time.

Face-to-face meetings allow the group to:

• Build shared context more quickly across complex topics  
• Work through architectural questions that require sustained discussion  
• Plan future work and document priorities  
• Strengthen the trust and relationships that make distributed collaboration work

As several members noted during the meeting, spending time together helps the group align on both technical direction and working practices, something that becomes especially important as new members join.

Topics discussed in London

Over the course of the week, the TAG covered a wide range of architectural and ecosystem issues affecting the Web.

The impact of AI on the Web and User Agents

One major theme was the growing impact of AI systems interacting with the Web. Discussions explored how concepts such as bots, automated agents, and “agentic” systems fit within existing web architecture and design principles.

Participants considered questions such as:

• How should the Web distinguish between humans, bots, and agents acting on behalf of users?  
• Do existing web principles need to adapt to this new environment, or should AI systems adapt to existing web norms?  
• How should the Web balance automated access with the sustainability of the broader web ecosystem?

The TAG also discussed the Web User Agents framing user agents duties duties (protection, honesty, loyalty), noting these are especially relevant as AI-driven agents interact with the Web:

• Which external developments (governance, regulations) should this guidance align with?  
• What measurable risks or harms could arise from misaligned duties?  
• How should user agents and their vendors be held accountable when internal choices diverge from these duties?

There is a need for careful architectural thinking as new forms of automated interaction become more common across the Web; that need falls directly under the TAG’s remit.

Architectural design principles for emerging technologies

The TAG spent some time discussing technical questions around emerging platform capabilities, including proposals involving downloadable components and large models running within browsers.

These discussions focused on architectural implications such as:

• Lifecycle management for global components  
• Privacy considerations, such as fingerprinting risks  
• Where computation should occur (device, browser, or remote service)

The goal is to capture these lessons in future TAG findings and design principles that can guide spec authors working in this rapidly evolving space. Some of this will update existing material, like TAG’s Ethical Web Principles, Privacy Principles, and of course, the Web Platform Design Principles.

Improving TAG processes and reviews

Another major topic was how the TAG organizes its own work. Members discussed how to balance different responsibilities, including:

• Design reviews for new web platform features  
• Writing architectural guidance and findings  
• Participating in broader ecosystem conversations outside the W3C

The group also explored ways to clarify the distinction between early design reviews, which help shape proposals, and later reviews, which help ensure the final work aligns with Web architecture.

These discussions are part of an ongoing effort to make the TAG’s work more transparent and useful to the wider W3C community.

Expanding participation through the TAG Associates program

Another topic that came up during the week was how the TAG can involve a broader set of contributors in its work.

To help with this, the TAG has created the TAG Associates program. The goal is to build a larger community around TAG activities, strengthen design reviews, and create a pathway for future TAG members.

TAG Associates are experienced contributors from the Web community who participate in parts of the TAG’s work without being formal TAG members. Associates are invited to attend many TAG meetings, may participate in architectural design reviews, and can contribute to the development of TAG findings and other documents. Each Associate works with a TAG member who serves as their mentor and primary contact.

Because the TAG reviews proposals across many parts of the Web platform, having a broader pool of expertise helps the group provide more useful architectural feedback. Associates can bring additional perspectives to design reviews and help connect conversations happening in different technical communities.

If you’re interested in contributing to TAG work, particularly by helping review emerging proposals, keep an eye on announcements about the Associates program and other ways to participate.

Looking ahead

The Web continues to evolve quickly, and many of the questions the TAG is discussing, from automated agents interacting with websites to where computation happens in the browser, are still taking shape across the community.

Meetings like this give the TAG time to step back from individual specifications and think about the broader architectural direction of the Web. They also give new and returning members the chance to build the shared context that makes distributed collaboration work. Our next face-to-face meetings will be in Vancouver, BC, Canada, in September 2026, and then another during the W3C TPAC  in Dublin, Ireland, in October 2026.

We look forward to continuing these conversations with the wider W3C community in the months and years ahead.

For those interested in the details of the discussions, the meeting minutes are available here.