May 30, 2011 16:41 GMT  ·  By

Windows Phone Marketplace, the mobile applications portal that accompanies Microsoft's Windows Phone operating system

, has reached another milestone, with over 20,000 applications now available for download for all Windows Phone users out there.

This is not an officially confirmed figure, but it comes from third-party tracking sites, which show that the app store is now 19,000 apps larger than it was when launched in October last year.

An impressive growth, that's for sure, equaled only by fast increase in numbers the developer ecosystem registered in the time frame.

Today, there are over 42,000 application builders registered to deliver software for the mobile operating system, at least this is what Microsoft confirmed only a few days ago.

When presenting the next Windows Phone release, Mango, Microsoft unveiled some numbers on the fast expanding Marketplace and Windows Phone ecosystem.

“We’re extremely grateful for all that the Windows Phone developer community has accomplished in a few short months and we’re excited to see what you can do with Mango,” a blog post from Matt Bencke, General Manager, Windows Phone Developer and Marketplace Experiences, reads.

“We recognize that the strength of our developer community and the Windows Phone ecosystem is a big reason why analysts are so optimistic about the Windows Phone ecosystem in predicting sales of hundreds of millions of units by 2015,” he continues.

Last week, Microsoft confirmed the inclusion of a number of no less than 17,000 applications in the Marketplace, with more to come.

The storefront is said to already include over 20,000 apps now, and is expected to become the top three mobile application portal in a matter of months, leaving Nokia's Ovi Store and RIM's BlackBerry World behind.

Mango, the next flavor of Windows Phone, should bring forth a series of new features for developers too, and a new set of tools to enable them come up with software for the OS.

“With the release of beta tools for Mango, we hope we’re taking another big step toward giving you exactly what you want from a platform so that you are inspired to create the next generation of amazing Windows Phone apps and games,” the said blog post continues.

The new Windows Phone Developer Tools 7.1 beta can be downloaded from Softpedia as well, via this link.