W3C

The Web Performance Working Group has published a Proposed Recommendation of Page Visibility Level 2. This specification defines a means to programmatically determine the visibility state of a document. This can aid in the development of resource efficient web applications. Page Visibility Level 2 replaces the first version of Page Visibility and includes a few Processing and IDL clarifications, as well as some new features. Comments are welcome through 14 November 2017.

The CSS Working Group invites implementations of an updated Candidate Recommendation of CSS Backgrounds and Borders Module Level 3. This draft contains the features of CSS relating to borders and backgrounds. The main extensions compared to level 2 are borders consisting of images, boxes with multiple backgrounds, boxes with rounded corners and boxes with shadows.

CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, in speech, etc.

The Timed Text Working Group has published a First Public Working Draft of TTML Profiles for Internet Media Subtitles and Captions 1.1. This specification defines two profiles of [TTML2]: a text-only profile and an image-only profile. These profiles are intended to be used across subtitle and caption delivery applications worldwide, thereby simplifying interoperability, consistent rendering and conversion to other subtitling and captioning formats.

The Web Performance Working Group has published a Proposed Recommendation of Cooperative Scheduling of Background Tasks. This document defines an API that web page authors can use to cooperatively schedule background tasks such that they do not introduce delays to other high priority tasks that share the same event loop, such as input processing, animations and frame compositing. The user agent is in a better position to determine when background tasks can be run without introducing user-perceptible delays or jank in animations and input response, based on its knowledge of currently scheduled tasks, vsync deadlines, user-interaction and so on. Using this API should therefore result in more appropriate scheduling of background tasks during times when the browser would otherwise be idle. Comments are welcome through 7 November 2017.

The Social Web Working Group has published a Proposed Recommendation of WebSub. This document provides a common mechanism for communication between publishers of any kind of Web content and their subscribers, based on HTTP web hooks. Subscription requests are relayed through hubs, which validate and verify the request. Hubs then distribute new and updated content to subscribers when it becomes available. WebSub was previously known as PubSubHubbub. Comments are welcome through 3 November 2017.

The Web Platform Working Group has published a W3C Recommendation of HTML 5.1 2nd Edition. This specification defines the 2nd edition of the 5th major version, first minor revision of the core language of the World Wide Web: the Hypertext Markup Language (HTML). In this version, a significant error with HTML 5.1 has been rectified, as noted in the Errata corrected section. Meanwhile, new features continue to be introduced to help Web application authors, new elements continue to be introduced based on research into prevailing authoring practices, and special attention continues to be given to defining clear conformance criteria for user agents in an effort to improve interoperability in the development of HTML 5.2.

The Web Real-Time Communications Working Group invites implementations of the following Candidate Recommendations:

• Audio Output Devices API, which defines a set of JavaScript APIs that let a Web application manage how audio is rendered on the user audio output devices.
• Media Capture and Streams (revised Candidate Recommendation), which defines a set of JavaScript APIs that allow local media, including audio and video, to be requested from a platform.

W3C announced today WebVR Authoring: Opportunities and Challenges Workshop, 5-7 December 2017, in Brussels, Belgium. The event is hosted by DigitYser.

The primary goal of the workshop is to bring together WebVR stakeholders to identify unexploited opportunities as well as technical gaps in WebVR authoring.

Participants in the workshop will:

• Share good practices and novel techniques in creating WebVR-based content
• Discuss existing and foreseen challenges in using WebVR to deploy content and services in specific usages
• Contribute to the unification of efforts for documenting and advocating the development of WebVR content

Attendance is free for all invited participants and is open to the public, whether or not W3C members. Our aim is to get a diversity of attendees from a variety of industries and communities, including:

• 360° video and VR content producers and distributors
• VR experience designers and artists
• 3D, VR and WebVR authoring tools and platforms
• authors of WebVR content
• experts in challenges and opportunities of VR for people with disabilities
• browser vendors

Expected topics of discussion include:

• Landscape of WebVR authoring tools
• Creating and packaging 3D assets for WebVR
• Managing assets for practical progressive enhancement
• Progressive enhancement applied to the variety of user input in WebVR
• Understanding and documenting WebVR constraints for 3D artists
• Optimizing delivery of 360° videos to VR headsets on the Web
• Practical approaches to building accessible WebVR experiences
• Mapping the impact of ongoing evolutions of the Web Platform (Web Assembly, WebGPU, streams) on WebVR authoring
• Impact of performance factors on authoring WebVR content
• Creating convergence on WebVR advocacy platforms

For more on the workshop, please see the workshop details and submission instructions.

Registration is available online due by 10 November 2017.