How to check what packages are installed on a RHEL5 system?

Question

A command that can be run by an unprivileged user is preferred.

Answer 1

Long ago I would have just used

$ rpm -qa

and possibly piped it through more. Looks like is still works.

Answer 2

dmckee's answer works perfectly well.

$ yum list installed

also works. No special privileges required.

Answer 3

rpm -qa --last >~/RPMS_by_Install_Date

this will also give you a list of when they were installed as well ... the file will be made in your home dir.