Windows Phone 7.5, nicknamed “Mango,” has been released today, according to Microsoft. Microsoft also reportedly struck a cross-licensing agreement with Samsung Electronics, under which Samsung will pay Microsoft royalties for technology used in the Samsung Android-based devices. The companies also agreed to work together on marketing efforts for Windows Phone.

In the months leading up to the Mango release, Microsoft has struck up several different partnerships, including one with Nokia and with HTC, an original manufacturer of Android- and Windows Phone-based devices. The HTC deal is similar to the one struck with Samsung.

According to Microsoft, many carriers and hardware devices have already received the update, with some having the software preinstalled on devices. Devices are listed by carrier and model here.

Al Hilwa, program director of application development software at IDC, said the update gives developers a plethora of features, user experience upgrades and PC connectability.

“Mango is finally coming out for existing devices,” he said. “The number of new features and capabilities compared to the devices that came out barely a year ago is stunning. Windows Phone developers and indeed those from other ecosystems like Symbian will feel like kids in a candy store with this release.

“Being able to showcase data and numbers in a homescreen tile with the prominence of the Metro interface has to be exciting. Other capabilities, like taking advantage of XNA and Silverlight in one app or finally being able to write augmented reality apps thanks to the camera APIs, should also be big draws.

“What do developers want? Well, as they look jealously at the multilingual Windows 8 development model, they may feel jealous, but the good news is that their skills and most of their code should move nicely and quickly to Windows 8. The ecosystem convergence between phone and PC will prove to be a huge Microsoft asset in its battle the next few years.”