Microsoft has made available to developers a beta build of its Mango Windows Phone operating system, as of June 29.



From All About Microsoft:

Microsoft also is making a new beta of the Windows Phone Developer tools available as of today, as well. Now known as the Windows Phone SDK (software development kit), the tools are in beta 2 (according to the download page) and can be used to develop applications for both the currently shipping “NoDo” Windows Phone operating system build, as well as for the Mango update.

Microsoft is making the Mango beta available via its create.msdn.com hub. Developers with a validated App Hub account are being allowed to flash the beta onto their retail phones. Developers are allowed to flash Mango onto only one phone per developer.Developers need to download the Beta 2 of the SDK before obtaining the operating system update.

  Windows Phone Mango operating system beta available to developers