On their blog the Unity3D team has announced the arrival of Unity 4.2, which bring support for Windows 8 and Windows Phone 8.
The Unity Engine is very widely used on a variety of platforms, and makes it easy for developers to create 3D games.
Microsoft has created a strategic alliance with the company, meaning developers will be able to publish their game to the Windows Store without having to pay the Pro fee.
The arrival of the toolset will mean it will be even easier for developers to port their application to Windows Phone. The Windows Phone Store already contains titles like Drift Mania created with the platform.
Microsoft and Unity are also running a contest with over $100,000 in prizes for developers creating original games for Windows Phone or Windows 8 using the tools.
The terms and conditions of the contest can be read here.
Read more details of the product at Unity3D.com here.