Will HTML5 make Silverlight redundant?

One of the great features of Adobe AIR v2 that was launched this month was its support for some of the 2008 draft of HTML5. The HTML5 specification was started in 2004, but the full spec will probably not be approved by W3C until around 2022. One might have thought that it would take years yet from now to reach the point where any browsers were remotely HTML5-compliant, but enough of HTML5 is published and agreed to make a lot of it possible, and Safari and Adobe have got there thanks to Apple’s open-source WebKit.

The race for HTML 5 has been fuelled by the demand by Apple and Google for advanced graphics, typography, animations and transitions without having to rely on third party browser plug-ins such as Adobe Flash or Silverlight. There is good reason for this haste: Flash doesn’t support touch-devices and has been slow in supporting hardware video decoders such as H.264. There is a strong requirement to do all that Flash can do in an open-standards way. Those with proprietary solutions remain sniffy. In AIR 2, Adobe pointedly disables the HTML5 and tags that allow basic playing of media content, saying that the specification is not final and there is still no standard for the supported formats, and adding that Safari implements a ‘disjoint set’ of codecs. Microsoft also has little interest in HTML 5 as it has so much invested in Silverlight. Google stands to gain by the Adobe AIR for Android as it will allow a lot of applications to be migrated easily to the platform, so sees Apple’s war on Flash as a way of gaining market share.

Why do we care? It is because HTML5/CSS3 provides facilities much far beyond HTML4, bring the reality of browser-based applications a lot closer. Probably most generally useful is the advanced typography: Safari and AIR already both support a way of reflowing text in a container across an arbitrary number of columns; Page-specific fonts can also be specified. Then there is 2D drawing, video, transitions, local storage, AJAX navigation and mutable DOM prototypes.

HTML5 is likely to provide base functionality that is required but it is too early to be certain that it will render Flash, Silverlight or JavaFX obsolete. In the meantime, Adobe Air provides the best vehicle for developing HTML5/CSS3 applications without a twinge of worry about browser incompatibilities.