Microsoft has officially released its Windows Phone 8.1 Developer Preview, allowing interested developers to test their Windows Phone apps against the latest version before the general release.

Just last week, Microsoft's Joe Belfiore announced that the developer preview of the company's latest Windows Phone 8.1 operating system would become available in "the first part of April," and the day has now come. Developers can take the new OS version for a spin and see how their apps work with it, giving them plenty of time to optimize everything before the software rolls out to the general public.

The new Windows Phone 8.1 is now available through the Windows Phone Preview for Developers program and will give you early access to the software. Keep in mind, however, that this build may still be buggy and it is not recommended to install it on your main phone, as the update will void your device's warranty at this point.

Instead, it is advisable to set up Windows Phone 8.1 on an unlocked device specifically meant for app testing. As expected, Windows Phone 8.1 Developer Preview comes with some prerequisites, as it is not the general release. First of all, you need to register for an app developer account. If you haven't done it already, you can do it here for $19 a year as an individual or $99 per year as a company. Interested parties can also register as developers at Microsoft's App Studio page at this link and create their own projects. For more details on how to register a Windows Phone device for development purposes, check out Microsoft's instructions here.

Once you meet the necessary prerequisites, the Windows Phone Preview of Developers will give you early access to pre-release updates for Windows Phone 8.1.

The latest version of Microsoft's mobile OS made its debut at the company's BUILD 2014 conference earlier this month, boasting notable improvements and new features over its predecessor. Windows Phone 8.1 highlights include a new Start screen, a long-awaited notification center called Action Center, as well as Microsoft's much-touted digital assistant Cortana, among other things.

The new Windows Phone 8.1 will roll out to existing Windows Phone devices over the next few months, while the first new handsets to run the latest OS out of the box will launch next month.