Dave Gutteridge dave@tokyocomedy.com wrote:
I've read on this list that CentOS is equal to Red Hat 9,
Nope.
or to Red Hat EL 4.
CentOS 4, yes.
Here's the breakdown:
CentOS 4 = RHEL 4 CentOS 3 = RHEL 3
RHEL 3 is based on Red Hat Linux (RHL) 9, with some latter updates coming from Fedora Core (FC) 1. Red Hat Linux 8 is largely compatible with RHL9/FC1.
RHEL 4 is based on Fedora Core (FC) 3. Fedora Core 2 is largely compatible with FC3.
The lineage: RHL8 -> RHL9-> RHEL 3 <-FC1 FC2 -> FC3-> RHEL 4
RHL/FC releases are on a 6 month cycle. RHEL releases are on a 18 month cycle.
That's why there is typically 2-3 RHL/FC releases per RHEL release. In the "good'ole days" before RHEL 3, Red Hat used revisions .0, .1, .2, etc..., and ".2" was the most mature.
In fact, Red Hat's first "enterprise" attempt was called Red Hat Linux 6.2 Enterprise (6.2E for short).