Yell is a program for analyzing diffuse scattering from single crystals using Three Dimensional Difference Pair Distribution Function (3D-∆PDF) method.
You can download the latest version of Yell for Mac and Windows here.
The documentation can be accessed at this link. The pdf version is also available at the latest release here.
The hypothetical iron-void example. Additional scripts for visualizing diffuse scattering and 3D-∆PDF maps are available for python and Matlab.