The WP7 operating system is built on Silverlight, XNA (the Xbox development platform), and the .Net compact framework. It's great news for developers who have invested time in learning Silverlight and XAML, because those skills will be directly transferrable to the mobile development space. To get an early start on development, all one needs to do is download the SDK and browse DZone or other sites for a plethora of tutorials on building applications and working with the WP7 OS.
The early reviews of Windows Phone 7 have been mostly positive, with almost no bugs found and no lags in the interface. Just a few weeks ago, select developers and testers started getting handsets running WP7. Here is what Engadget had to say about the early version of the OS:
"Windows Phone 7 is easily the most unique UI in the smartphone race right now ... We were extremely surprised and impressed by the software's touch responsiveness and speed ... Let's just put this up front: the keyboard in Windows Phone 7 is really, really good ... we've got to say that Web browsing on Windows Phone 7 is actually a really pleasant experience ..."
ZDNet mobile device blogger Matthew Miller was especially impressed with the stability of this early release:
"I ... am much more impressed with the phone and Windows Phone 7 operating system than I thought I would be at this stage of development. The phone NEVER crashed or locked up on me and I did not experience any bugs or other anomalies to report to Microsoft so far ... The user interface is completely different than any other smartphone operating system and is a nice, refreshing change."
Some useful features are still missing from the preview, such as copy/paste and multitasking, but these could be available in the final version. The news is mostly good for Microsoft, who needs to deliver a product that's unique, but also solid and easily usable. The main challenge now is to catch up to its competitors, which already have tens of millions of users. So far, developer interest has been significant.