> i worked in many different companies, and all of them used centos in order to have "proper enterprise linux" but for free. The only cases when real redhat was

> i worked in many different companies, and all of them used centos in order to have "proper enterprise linux" but for free. The only cases when real redhat was used is for something that actually required it by licensing/support terms - like Oracle, or alternatively contractual obligations for SLA. I worked on a product that allowed both RHEL and CentOS, and then moved to a different one that mandated RHEL with a supported contract. The latter was far less stressful to deal with, because any time there was an OS issue, we could pretty easily tell them, "Go to Red Hat." The shops that were on CentOS on the other product tended to be small businesses (and cheapskates), and every time an OS issue arose, it was a screaming match trying to convince them that we're not going to fix their OS for them.