And the success of Red Hat comes to no small amount from other software companies, which certify their software products often on Red Hat only. That means, if you are trying to get technical support for that software, it might depend on running on red hat. Of course, the software would in principle run on most other Linux distributions, especially Fedora, but I have seen smaller incompatibilities when running not on Red Hat. So this creates a certain market pressure to use Red Hat.