Version 6
Information about the TOPAS-Academic software, including pricing can be found at the following link;
http://www.topas-academic.net/
Once downloaded, follow the instructions in the README.txt file to install.
Tutorials
An excellent range of tutorials can be found here.
Macros
A list of user macros can be found on the TOPAS wiki, here.
The macros for PDF refinements written by Phil Chater can be found on his GitHub page, here.