RMS is focused on the four freedoms.  Open Source licenses which don&#x27;t provide those freedoms he considers to be nonfree.
In the extreme case, you can read the source, but all rights are reserved, as you mentioned.  Java is the highest profile project that existed this way until it was finally open-sourced.  You could read the source, but were not allowed to really do anything with it.  As such, it was not only non-free, but also not open source.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Java_(software_platform)#Licensing" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Java_(software_platform)#Licen...</a>