I can’t seem to find a decent announcement post on the QNX website, so here’s Thom Holwerda writing on OSNews:
Well, it seems the company is trying to reverse course, and has started courting the enthusiast community once again. This time, it’s called QNX Everywhere, and it involves making QNX available for non-commercial use for anyone who wants it. No, it’s not open source, and yes, it requires some hoops to jump through still, but it’s better than nothing. In addition, QNX also put a bunch of open source demos, applications, frameworks, and libraries on GitLab.
Notably there is now a pre-built image for the Raspberry Pi 4 with an accompanying book: Introduction to the QNX RTOS with Raspberry Pi by Elad Lahav. The source of the book is also on GitLab.
Many years ago I used QNX for a project at university. We used its built-in RPC mechanism to coordinate behaviour across multiple machines and wrote a GUI using its built in toolkit. I remember QNX being quite usable, with a familiar and capable GUI. It was also quite compact, having a version that could run from a single floppy disk. The system was quite responsive due to low system requirements and real-time nature.
QNX was also quite straightforward to program for, with a comprehensive suite of C++ libraries for the system. I can certainly recommend playing around with it if you’re interested in learning about alternate operating systems, especially hard real-time ones.