Our software is free, as in freedom.

You have the same rights whether you make a donation or not. Not everyone can afford to give some money, and we’re fine with that. Note that we welcome any kind of contribution, there’s always something to do, like translations, fixing bugs, contributing to the doc, creating examples and tutorials…

There’s always a download link available on the official website (rxlaboratory.org) to let you download the tools for free.
Just look for the links which read “I don’t want to contribute and support free software.” or “Sorry, I can’t afford to support RxLaboratory at the moment.”

Do NOT download Duik from anywhere else! You probably won’t find the latest version, and you may just end-up with a virus too.