With Windows 8 now formally launched, it's time to get your hands dirty working on it. 

A number of extensions and toolkits have been built and released on various sites to enable developers achieve better productivity and faster development. Here are some of them:

**Callisto: A toolkit for XAML Windows 8 Store apps**

Built by Tim Heuer, it is a toolkit of sorts for XAML-based Windows 8 Store apps.  He started it  during the Consumer Preview and has put it up on github. 

[https://github.com/timheuer/callisto][1]

**WinRT XAML Toolkit**

The Windows Runtime (WinRT) XAML Toolkit can be found at Codeplex and contains a number of controls and helpers that help you build Windows 8 Store applications.

[http://winrtxamltoolkit.codeplex.com/][2]

**Windows Azure Toolkit for Windows 8**

This toolkit makes it easy to build a cloud service to support rich Windows Store apps. It has all the tools to enable easier development of a Windows Azure service and deploy it to users. The toolkit includes Visual Studio project templates for a sample Windows Store app and a Windows Azure cloud project. 

http://watwindows8.codeplex.com/


**Windows 8 apps: Multilingual App Toolkit** 

This toolkit is an extension for Visual Studio 2012 helps you localize your Windows app with translation support, translation file management, and editor tools.

http://msdn.microsoft.com/en-us/windows/apps/hh848309.aspx


  [1]: https://github.com/timheuer/callisto
  [2]: http://winrtxamltoolkit.codeplex.com/