Microsoft Chairman and Chief Software Architect Bill Gates Wednesday used his keynote address at the first Microsoft Mobile Developer Conference to signal Microsoft's intention to play a major role in the mobile software business.The Redmond, Wash., software maker intends to make it easy for developers to create applications for platforms ranging from PCs to intelligent wireless wristwatches, Gates told a large crowd at the conference, which is being held here alongside\u00a0CTIA Wireless, a three-day showcase of wireless hardware and software that ended Wednesday."There is no application that won't be able to fit on these devices," Gates said.The centerpiece of Gates' speech was the final version of .Net Compact Framework, which will be available worldwide starting Thursday. The framework is designed to extend the benefits of Microsoft's .Net technology, such as Web services capabilities, to mobile devices.The new technology will be included in Visual Studio .Net 2003, which Gates said will provide a consistent development model for applications on a broad range of devices. That tool is scheduled to become available April 24. Developers will be able to download the .Net Compact Framework beginning Thursday and deploy applications with it immediately using the beta version of Visual Studio .Net 2003, said David Rasmussen, lead product manager for .Net Mobility Platform at Microsoft, in a briefing Wednesday before the keynote.The .Net Compact Framework will support development of software for any device that runs Windows CE Version 4.1 and later, according to a Rasmussen. That includes devices based on the Pocket PC 2000, Pocket PC 2002 and Pocket PC Phone Edition reference platforms.The keynote presentation also included a demonstration with a Smartphone device, a more compact platform that will be supported in the next release of the framework. Developers also will be able to write applications for smart watches, which use Microsoft's SPOT - Smart Personal Object Technology -\u00a0platform, using a subset of .Net Compact Framework, Gates said.To promote the new framework, Microsoft will give away the ViewSonic Corp. V37 Pocket PC to the first 25,000 qualified Visual Studio customers. The V37, introduced Wednesday, is a PDA with a 3.5-inch display, a 400MHz Intel Corp. XScale processor, 64M bytes of RAM and 64M bytes of ROM. It will include the .Net Compact Framework in ROM. Information about the promotion will be available here.