Q. What is a "rolling" release?

A. The "rolling" releases are our test releases. They are the equivilant to what another vendor calls "rawhide". We call them rolling because they are always rolling along and rarely stable.
They are not meant to be stable. They are not meant to be used in a production enviroment. They are for testing purposes only. Depending on where we are in our testing the rolling can be a beta, a release candidate, and for a short time, will even match a current release.
The development team of Scientific Linux does not garantee that a rolling release will work. We want to make that clear. Although the rolling releases might work just fine for the majority of the time, we might also just happen to be testing some product that does something you don't want it to do.

Q. What is a "x" release, as in 4x?

A. The "x" releases are links to the latest stable release.
An example would be 4x. At the time of this writting, 4x/i386 is pointing to 44/i386. At the time 45/i386 is released, the link will be moved from 44/i386 to 45/i386.
This was made to ease documentation, and to allow people to consistantly be updated to the latest release if that is what they want.

Q. What is the numbering scheme of the releases?

A. For every release there is a major and a minor number. These are the first and second number respectivly.
The major number corresponds to The Upstream Vendor's enterprise release number. The minor number corresponds to their Update number.
So Enerprise Linux 5, Update 2 corresponds to Scientific Linux 5.2.

Q. Why do the Scientific Linux 3.x releases all start with 3.0?

A. This was for historical reasons.
At the time The Upstream Vendor released Enterprise Linux 3, they had always followed their release with another release that has a number after it. Such as 7.1 then 7.2, then 7.3. Even their enterprise releases followed this pattern, with Enterprise Linux 2 and then Enterprise Linux 2.1.
So, even though Enterprise Linux 3 didn't say it was Enterprise Linux 3.0, we expected there to be a Enterprise Linux 3.1. And to keep our naming convention from having to change from 2 to 3 numbers, we started out with Scientific Linux 3.0.1, expecting there to be a Scientific Linux 3.1.1.