WICD mobile: MashLite?


By Dr Paddy Byers

C Enrique Ortiz pointed out the latest W3C mobile content initiative, WICD Mobile 1.0. It is based on the generic Web Integration Compound Document (WICD) specification, which is a way of combining content in multiple disparate markup languages (eg SVG and XHTML) into a single entity that can be navigated seamlessly and in which scripts in each part can (in principle) gain access to the DOM of the containing or contained entities. The WICD Mobile variant is essentially just a profile, demanding certain XHTML and CSS capabilities, certain SVG capabilities, and certain DOM and scripting capabilities including XMLHttpRequest.

This specification simultaneously overcomes several problems that are faced when trying to implement applications or services using the constituent technologies standalone. Until now, SVG (Tiny) on mobile had in practice been limited to an asset format (ie a way of delivering scalable images as an alternative to bitmaps) because limited scriptability meant that it could not support application development in its own right. Similarly, a vector graphics capability overcomes the drawing limitations of XHTML and CSS, especially when creating content that needs to adapt to multiple screen sizes. WICD mobile, in principle, is therefore able to combine the visual richness and interactivity of Flash Lite and the asynchronous connectedness of AJAX, all based on the browser delivery platform. It could be said that this is the W3C’s answer to Flash Lite as a mobile application development platform; the ultimate environment for mobile web apps and mashups.

So, what are WICD’s strengths and weaknesses relative to Flash Lite and will it succeed?

The key technical difference is that there is no timeline and no frame-based animation as there are in Flash. Instead, apps would essentially work the same way as AJAX scripted XHTML apps, being primarily event-driven through input events and network events, except that there is a richer set of rendering tools available and support for scripting of composite vector graphic entities. Flash components (supported in Flash Lite 2.0) would be essentially analogous to WICD-M widgets.

WICD-M potentially supports better integration with platform features – eg leveraging platform (and hence hardware-accelerated) multimedia systems instead of proprietary formats as with Flash; and the embedding of arbitrary scriptable entities within a DOM in principle allows platform services to be accessed in a more scalable way than is possible with the frozen and inflexible Flash Lite platform APIs.

Flash Lite already has a head-start, and its deployment onto the latest Nokia phones has stimulated a development community to explore its potential; WICD mobile, on the other hand, isn’t supported by any mobile browser yet, and even rich XHTML (including competent DOM, javascript and XMLHttpRequest) has very limited support.

However, the biggest advantage that Flash has is the content development toolchain and its associated development community. Powerful tools are the key to unlocking the potential of the vector graphics environment – and this is the true power of what Adobe is bringing to mobile with Flash Lite. There is simply nothing comparable for WICD mobile; until there is, its progress in attracting content developers is likely to be very slow, and this will inevitably impact its proliferation into mobile.