what is the difference between various qnxs?

hi, i’m new to this OS and i would like to understand something.
i found the iso for qnxncXX and qnxrtpXX, which is the difference?
(i excuse in advance for my english if there’s some error, i’m italian… :slight_smile: )

they used qnxrtpXX filename in the earlier days (6.0, 6.1) when there was no NC, SE, PE differences. Starting from 6.2.0, you can only download the stripped down Non Commercial (NC) version, with a filename qnxncXX, for free.