Microsoft has released the Windows Mobile 6.5 SDK DTK for developers.

The Windows Mobile 6.5 Developer Tool Kit adds documentation, sample code, header and library files, emulator images and tools to Visual Studio that let you build applications for Windows Mobile 6.5. This document contains important information about this package. For general information about writing software for Windows Mobile, please see the Windows Mobile Developer Center. The Windows Mobile 6 SDK must also be installed in order to use any of the Windows Mobile 6.5 Gesture API or samples. Windows Mobile 6.5 Developer Tool Kit comes with Emulator Images.

A new set of APIs is being introduced that will enable application developers to take advantage of the new Windows Mobile 6.5 touch gesture framework. The gesture APIs allow an application to handle touch gesture input and provide a visually consistent experience with the rest of the device UI. Note that the gesture APIs are only available on the Windows Mobile Classic and Professional SKUs. The headers and libraries are installed in the Windows Mobile SDK\Pocket PC\ folder. Samples that make use of these APIs are installed into the Windows Mobile 6.5 Developer Tool Kit\Samples\ folder.

As mentioned above, this release also includes the Windows Mobile 6.5 emulators:

[pictures by Geoffrey Emery]

You can download the package from Microsoft here, so you can finally get to work on your Windows Mobile Widgets. Over on the Windows Mobile Blog, Jorge Peraza wrote a great tutorial on how to get started with widgets.

After you’ve created your widgets you can upload them to the Marketplace (registration currently only open to English language markets).

Edit: Changed SDK to DTK
Reason: The Windows Mobile Developer Toolkit (DTK) is not a Software Development Kit (SDK) as you will still need to install Microsoft Visual Studio® 2008 and the Windows Mobile 6 SDK prior to running the toolkit installer. This is explained in SDK, DTK, DRK: WTF?! over on the Windows Mobile Blog. Thanks Alber1690 :)