There is an embedded product from Microsoft that is not marketed at all, open-source based, community-driven and free for OEMs to put on their devices. And it is successful!
It first was declared dead a few years ago, but then thankfully moved into more silent waters by the Visual Studio team.
The product I am talking about is the .NET Micro Framework. Developed at Microsoft Research it is a .NET runtime to put directly on small devices. You can use an underlying OS, if You want to, but there is no real need for this.
The really nice thing about the .NET MF is that you can use c# and Visual Studio to talk directly to hardware such as processor pins, busses, which gives you an easy access to sensors and actors in managed code.
Slowly, but steadily and despite the fact that no-one in the Microsoft marketing machinery has been really pushing (except the MF team itself), the .NET MF has been becoming increasingly popular among several innovative hardware manufacturers as well as a lot of hobbyists. All of them contributing and advancing the functionality and quality of the project.
One of the recent highlights is .NET Gadgeteer, a rapid prototyping platform, which is fun to play with but at the same time offers everything you need to test and develop your next generation embedded device.
Check it out or even better join one of my upcoming courses on this great and productive embedded platform! 1.5 million devices are already out using .NET MF!
Small is beautiful!