This week Palm has finally released their SDK for Palm Pre development and Google have continued in their announcements that web technologies will be the eventual approach for mobile phone development. Nokia's WRT technology is now well established and grown signficantly with S60 Ed5 services APIs.  Meanwhile the real issue with this technology has been the speed of execution of Javascript is being solved using better Javascript engines and the emergence of new HTML5 functions allows browsers to get closer to native speed execution.

The common approach of all these methods is to use HTML, CSS and Javascript as the basis for writing applications.  Each manufactirer is enhancing their Javascript libraries to so that there is API access to system functionalities such as media, sensors, GPS, address book and other core phone functions.  Where some manufacturers have not opened up their APIs yet (eg Apple) other group are providing frameworks to do so (eg Phonegap providing plaform access for iPhone and Android).

Additionally W3C have their own widget development metholdolgy which is being supported by a number of operators via the jil.org. Ths technology is very close to WRT and indeed they provide very good tools to convert between WRT and the W3C format.

My own view is there is now a need for someone to create a framework sitting on top of all these technologies - they are all amost the same/compatible with slightly different wrappers and different syntax for the APIs.  The real need for all developers is to write their applications only once for all platforms - a framework can take away these diferences.

My own experience of working with these technologies is to develop using Nokia's WRT to create working applications.  I then use Phonegap to create the same applications running the same code on iPhone.  Its not as easy as it should be - there are all sorts of gotyas, for example scrolling is done differently on iPhone and Android to how normal browsers work, but it can be done and its the future for a new way of doing software development.