Microsoft released the software for the kick off of its developer focused conference, being held this week in Redmond, Washington.

In Tuesday's keynote address at Build, Microsoft CEO Steve Ballmer admitted that, thus far, Windows Phone has not sold in significant numbers. He said he expects this to change with the recent releases of Windows 8 and Windows Phone 8.

"I think most folks in the room know that Windows phone is a small volume player," he told the audience of developers. "But we have the most differentiated approach to the market. We have absolutely killer hardware and there will be hundreds of millions of Windows users who will want a Windows phone," he said.

"With the launch of Windows Phone 8, the phone enters in full fruition as a first class member of the Windows family," Ballmer said. Nokia, Samsung and HTC are all in the process of releasing Windows Phone 8 handsets.

provides a stand-alone IDE (integrated development environment), using the Visual Studio Express 2012 edition, for developers to build windows Phone 8 applications. It also provides an add-in to the Visual Studio 2012 Professional, Premium or Ultimate editions.