# Switching These pages are for users of TOPAS, GSAS-II and FullProf, and say what rietx does the same, what it does differently and how it was validated. - [rietx at a glance](at-a-glance.html.md) lists the data rietx fits and each feature with what it was checked against. - [Coming from TOPAS](topas.html.md), [Coming from GSAS-II](gsas2.html.md) and [Coming from FullProf](fullprof.html.md) give the differences in concepts, paired examples, and how to move a file across. - [Validation against other codes](validation.html.md) gives each comparison with its protocol and its numbers. - [Roadmap](roadmap.html.md) lists the milestones in progress and planned. - [Names in other programs](../reference/foreign-names.html.md) maps each parameter to its name and unit in the four programs.