The W3C Web Application Formats Working Group is chartered to develop languages for client-side Web Application development.

Note: The charter for the working group has been extended to 31 May 2008.

Current priority work items

The Web Applications Working Group charter made it clear that the need would likely arise for the group’s work to focus at times on deliverables that could not have been anticipated at the time the charter was drafted, as evidenced by the following statement in the charter:

Given that the rich Web client area is in a phase of rapid development, the Working Group may become aware of the urgent need for standardization of a technology not explicitly listed in this charter, but still in the scope of the Working Group.

The group’s work is currently directed toward two specifications in that category:

Access Control for Cross-site Requests

Defines a mechanism to enable client-side cross-site requests. It defines a request algorithm for GET and non-GET requests that specifications that want to enable cross-site requests in the technologies they define can use.

Widgets 1.0

Widgets are a class of client-side web application for displaying and/or updating local or remote data, packaged in a way to allow a single download and installation on a client machine or device.

Four Widgets specifications have been published. See the sidebar for their names and locations.

Other deliverables

Other deliverables outlined in the Web Applications Working Group charter include:

XML Binding Language (XBL) 2.0

XBL2 is an extension to the sXBL specification developed jointly by the SVG and CSS Working Groups. XBL is a declarative language that provides a binding between custom markup and existing technologies. This enables an extensible framework for custom controls and the MVC (model, view, controller) methodology.

A Candidate Recommendation for XBL2 was published on 16 March 2007. See the public announcement for more details.

Note: The Web Application Format Working Group is currently seeking implementations and test suite contributions for XBL2.

Guidelines for Web applications

This may include a list of technologies to support in order to provide a standard interoperable Web application development platform.

Interoperability test suites for relevant deliverables.

Following the W3C process for specifications.

Education and outreach material for Web developers.

This may take the form of a weblog or W3C Notes with suggestions and guidelines for developing accessible Web applications.

Deliverables on which work has ended

Specification of a declarative format for applications and user interfaces.

This specification was originally described in the charter as:

...based on an existing application/UI format, such as Mozilla's XUL, Microsoft's XAML, Macromedia's MXML or Laszlo Systems' LZX, provided the owners of the format are willing to contribute. The format should allow embedded program code. This format, combined with the deliverables below and existing technologies including XHTML, CSS, XForms, SVG and SMIL, should provide a strong basis for rich client application development.

However, the group made a decision to stop work on this item and to instead publish (on 12 September 2007), a Note documenting that decision.

More details on the Working Group's deliverables and roadmap are found in the charter.

The Working Group values any input from the community regarding its deliverables. Please use the public mailing list (details in the sidebar) to give any feedback.