How can I find out whether a specific RedHat release (RHEL4, RHEL5...) contains a certain package (or a certain version of a package)? For Debian and Ubuntu, there's packages.debian.org and packages.ubuntu.com; is there a similar web site for RedHat?
Note: I don't want to have to install all the releases just to check some package version :-)
For starters: http://distrowatch.com/table.php?distribution=redhat has a list of the important versions, but certainly does not list all package versions.
The best you can do, as it seems, is to check the FTP directories of the source packages:
Keep in mind that RedHat has the habit of patching software to hell and back, so the version number might not have to much in common with the actual release, especially for the kernel.
If you have your yum repositories set, you can use "yum search " to see if it exists, or "yum list" to see all available packages.
Looks like Fedora is now working on an online list of packages (PackageDB - see http://fedoraproject.org/wiki/Infrastructure/PackageDatabase). The current version is available at https://admin.fedoraproject.org/pkgdb/ . It doesn't seem to know about all RHEL4/RHEL5 packages, though.