ASP.NET Mobile Controls 391 Conclusion Developing mobile applications can be quite a complex task because of differences in browser presentation models and gateways. Like it or not, the market for wireless devices is fragmented, although this fragmentation is possibly stronger in Europe than in other parts of the world. So to be on the safe side and deploy effective applications, you should multi-author your application for each relevant class of devices. Writing multiple applications is not usually an attractive prospect to de- velopers and managers, who are understandably reluctant to give the green light on such projects. In the wireless world, though, the difference between devices is too large to be effectively addressed in all cases even by a well-written library such as the ASP.NET mobile controls. The need to deal with radically different sets of capabilities forces developers to implement navigation models, data entry capabilities, and strictly device-specific commands. If you're going to build mobile applications for multiple devices, your best chance is to endow yourself with a server-side programming library that abstracts the presentation of content from the underlying platform. ASP.NET mobile controls do just this and much more. There are several key plusses in ASP.NET mobile applications. For one thing, ASP.NET mobile controls are fully integrated with the .NET platform, meaning that you can leverage the full potential of the .NET Framework with its over 7,000 ready-to-use classes. In addition, the Mobile Designer integrated with Visual Studio .NET 2003 lets you build mobile ap- plications in an intuitive manner and with a very short learning curve if you're already a .NET de- veloper. (Also Web Matrix supports mobile projects.) Finally, mobile development in the .NET world is language agnostic. Aside from the .NET platform, other server-side libraries have been developed in the community with the declared goal of abstracting both the differences in the vendor's implementations of the WML language and the hardware device capabilities. An example of this approach is the Open Usability Interface (OUI) originally developed by Openwave and then transformed into an open- source project. With a more limited scope than ASP.NET, OUI is optimized for rendering on Nokia and Openwave browsers. OUI is available for download at http://oui.sourceforge.net. In this chapter, we presented an overview of ASP.NET mobile controls, trying to emphasize all relevant aspects but not digging too deep into any of them. Building mobile applications, especially for multiple devices, is a huge topic that deserves an entire book of its own. This chapter concludes the overview of ASP.NET controls. In the next part of the book, we'll look at programming aspects that are essential for setting up real-world ASP.NET applications. We'll return to controls in Part V in time to cover custom controls. Resources · Building Microsoft ASP.NET Applications for Mobile Devices, Second Edition , by Andy Wigley and Peter Roxburgh (Microsoft Press, 2003) · Mobile ASP.NET Web Applications (http://www.asp.net/mobile/)