The DirectX Toolkit has been on CodePlex for years, ever since they deprecated D3DX and all of the math, texture and model handling code therein when they switc

The DirectX Toolkit has been on CodePlex for years, ever since they deprecated D3DX and all of the math, texture and model handling code therein when they switched to the DirectX SDK versions that was included in the Windows SDK (Windows 7, I believe? The last standalone DirectX SDK download is the July 2010 version).