Learn about the math of 3D rendering, and how to convince a 2D graphing calculator to produce 3D images.
Or: why the physics engine is not your friend.
A long response to a short StackExchange question.
And iTunes, Windows Media Player, and everything else, with just a little bit of Windows API magic.
How to build libgit2 from source, install it on your computer, and use it in a project without linker errors.
An engine plugin for Unreal Engine 4 that makes it easy to create interactive objects in VR.