The first taste of gaming came courtesy of "The Harvest," a proof-of-concept title that shows Xbox LIVE Achievements, destructible terrain and a 3D interactive environment. It was developed by Luma Arcade using XNA Game Studio 4.0 in about three weeks of development time. Microsoft also outlined how developers can write their own programs using Silverlight, Visual Studio 2010 Express for Windows Phone, and Expression Blend 4 for Windows Phone. What's more, all developer tools are available for download now at no cost.
Compatible phones won't be ready for a while, of course, but developer can use the PC emulator to start coding. Later this year they'll be able to sell their programs using a new Windows Phone marketplace, which will support one-time credit card purchases, mobile operator billing and advertising-funded applications. It will also allow customers to try applications before buying them and developers will be able to cross-promote their applications through deep linking.