The future of applications: W3C TAG perspectives

Henry S. Thompson
School of Informatics
University of Edinburgh
W3C Technical Architecture Group
28 March 2011
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1. The World Wide Web Consortium

Founded by Tim Berners-Lee to sustain the value of the Web for everyone and "lead the Web to its full potential"

Hosted by MIT in US, Keio University in Japan and ERCIM in Europe

~60 employees, about half working remotely

Over 300 members: organisations and companies

Recently awarded substantial support from ISOC

Standards work carried out by Working Groups made up of member representatives and invited experts

100s of existing Recommendations, dozens in progress from >50 WGs

Mostly 'horizontal' technologies

2. The Technical Architecture Group of the W3C

Originally the Director (Tim B-L) was responsible for maintaining consistency across activities

As the Consortium grew and the scope of its activities enlarged, this task became impossible

The TAG was established eight years ago to pick up and broaden this task

And, perhaps most importantly for tonight's panel

[H]elp coordinate cross-technology architecture developments inside and outside W3C

(From the TAG's formal charter)

3. TAG membership

Tim Berners-Lee ex officio

Three appointed members

Five elected

Plus Yves Lafon, staff contact

Weekly 'phone conferences, four face-to-face meetings yearly

4. A parenthesis on the meaning of the word 'architecture'

I suspect that the IETF community and the W3C community have different initial examples in mind when they hear the word architecture

"The architecture of the Internet"

"The architecture of the World Wide Web

5. Architecture of the World Wide Web

A grandiose concept

A document

6. Grandmother observations about the Web

"Global naming leads to global network effects"

"To benefit from and increase the value of the World Wide Web, agents should provide [http:] URIs as identifiers for resources"

7. More from Grandma Webarch

It's good for the ownership of a name (URI) to be manifest in the form of that URI

"A URI owner should not associate arbitrarily different URIs with the same resource."

"Agents do not incur obligations by retrieving a representation."

"A URI owner should provide representations of the resource it identifies"

8. In a nutshell

The Web works because you can

9. Web architecture and applications

All those nice pithy observations

The Web is evolving

10. The rise and rise of port 80

HTTP, HTML and the browser have come to increasingly dominate the Internet

Tensions and problems have arisen because HTTP, HTML and the browser were not designed to be a distributed application delivery platform

Hence the TAG's work on Web Application Architecture

11. The W3C vision of the Open Web Platform

'Open Web Platform' is the W3C's umbrella term

"A platform for innovation, consolidation and cost efficiencies"

(Jeff Jaffe, W3C CEO)

display of OWP standards
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Courtesy of W3C
OWP stack diagram
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Courtesy of W3C

12. HTML5 at the center

Standardising the Open Web delivery platform

Expanding and clarifying HTML

There are many demos available: here's a collection of linked (click on 'next') HTML5 demo pages from Philippe le Hégaret of W3C

13. Behind the scenes: Javascript APIs

Three layers of specification:

  1. Javascript the language, aka ECMAScript
    • ECMA TC 39 is in charge
  2. Web IDL, for API definition
    • W3C's Web Applications WG is in charge
  3. Individual APIs
    • Web DOM Core API, Drag Drop API, Text Selection API, Undo History API
    • 2D Context API, Web Storage API, WebSockets API, Web Workers API
    • Web Messaging API, Geolocation API, Indexed Database API, Microdata API
    • RDFa API, Element Traversal API, XMLHttpRequest API, Web Notification API
    • DOM Level 3 Events API, Navigation Timing API, Multi-touch Events API
    • CSSOM View Module API, Selectors API, File API, (WebGL API)
    • Resource Timing API, User Timing API, Messaging API, Device API

Maybe be client-side only

May be intended for implementation

14. The TAG and the IAB

So far I've talked about how we saw ourselves

WebArch (the document) was (mostly) squarely within W3C territory

Some overlap is unavoidable

But it needs to be recognised and managed

15. Example 1: Scalability

Right on the edge between W3C and IETF

Several years ago, W3C discovered that the HTML DTD and other similar static resources are being accessed up to 500M times/day, often from the same client

Architectural issue:

Practical issues:

The W3C's current response:

Is this a Best Practice?

16. Priorities

The W3C recently published its priorities going forward:

  1. Powerful Web Apps
  2. Data and Service Integration
  3. Web of Trust
  4. Television, Mobile and the Web of Devices
  5. One Web for All

The TAG has organised its current activities under four broad headings, which are broadly in line with those institutional goals:

  1. The future of HTML
  2. Privacy
  3. Web Application Architecture
  4. Core Mechanisms of the Web

17. New areas for Web/Internet Architecture

All of the following (relatively) new webapps-related TAG issues are, it seems to us, IAB issues as well:

Some of these, e.g. privacy, are areas where active cooperation is already under way;

In some, e.g. IPv6, the TAG is happy to look to the IAB for guidance;

Others, e.g. the diversification of fragment identifier usage, are areas where the TAG has, at least so far, been driving.

18. Example 2: Privacy

Some small concrete steps underway in this huge and poorly-delimited area

Minimization principle

Do Not Track

19. Privacy, cont'd

The view for 10,000m: "Information Accountability" Abelson, Berners-Lee et. al., CACM v. 51, No. 6, 2008

20. Example 3: Fragment identifiers and client-side state

Increasingly, what is displayed on the browser page is constructed by JavaScript on the client using bits retrieved from the Web in the background

To allow bookmarking, sharing, back functionality etc. requires the page URI to be updated to record such changes in browser state

But this in turn renders the distinction thus captured invisible to search engines

The situation is

Ashok Malhotra Repurposing the Hash Sign for the New Web (work in progress)

21. Thinking again about Web Architecture

Or, when does a quantitative difference become qualitative?

Browsers have always had to compute what people see on the screen

That hasn't changed

None-the-less the old naive picture

is a best a pretty misleading way to think about things today

With so much of the action now taking place client-side

With so many new APIs/protocols

22. Conclusions

The IAB and the TAG have interests in common going forward

A monthly W3C-IETF liaison call, plus one or two by-chance overlaps in personnel, are probably insufficient to manage the cooperation which is necessary to address these common interests effectively.

At the end of the day, there is only one reason for a standards body to exist

The IETF and the W3C should and, I hope will, do better at institutional interop :-)