From this site you can download copies of the Gudrun and EPSR programs.
Gudrun is a data analysis package that allows the user to go from the raw scattering data obtained in neutron and x-ray scattering experiments to Differential Scattering Cross Section (DCS) and then to Pair Distribution Function (PDF).
EPSR, which stands for Empirical Potential Structure Refinement, is a computer simulation package that allows the user to develop three-dimensional structural models based on the extracted DCS data. It currently works best for liquids and glasses, but a version for crystals might appear at some stage.
Both packages are being updated at regular intervals so it is worth revisiting this site from time to time to check you have the latest version.
In addition there is a User Forum for each package where users can exchange information or share experiences.
If this site proves popular it may be expanded in the future, according to demand.
To download the programs or contribute to the User Forum you will need to login.
Many thanks and I hope you enjoy!