The .NET Micro Framework is an open source platform that enables you to write applications on resource constrained devices that run on a microcontroller with just a few hundred kilobytes of RAM and storage. Developers can use Visual Studio, C#, and .NET knowledge to write embedded applications without having to worry about the intricacies of each microcontroller running on their embedded device. The .NET Micro Framework is open-sourced by Microsoft Open Technologies. This video provides an introduction to the .NET Micro Framework.
You may think that there is much in SQL Server that appears to work as if by magic? And you would be right! But despite this magic, everything is actually quite easy to understand. This 500-level report contains information about the internal data storage format in SQL Server (MDF files), as well as about how you can work with the data using only a hex editor. You will learn about how SQL Server stores internal metadata for objects and about how you can find and read the data on the disk.
This was a fun one! I spent some time with Jimmy Bogard on his tremendously successful open source project called AutoMapper. If you have not heard of it then you have no doubt, like me, wasted precious keystrokes on manually converting from one object type to another by mapping properties in code. AutoMapper helps eliminate the need for that completely and goes a step further by even making queries to a database more compact and concise.
He also spends some time talking about what makes for great open source projects - oddly enough its not what I thought he would say.