What is the difference between the rpm and .tar.gz installations? Which one is better?
The RPM package includes Java, so you don’t need to install it. If you want to install Openfire you can simply type
rpm -ihv openfire-3.3.3-1.i386.rpm
The .tar.gz is a little bit more complicated. The advantages of the .tar.gz are:
smaller package
you can use an already installed Java, even a newer Version for some security fixes.
update Openfire with a extreme short downtime. You can calmly prepare the new openfire version in another directory. The shutdown openfire, rename directories and start Openfire again. Takes just 5 seconds or so…
If you just want to run Openfire, you will need a JRE (Java Runtime Environment). Its shipped with the Openfire RPM. If you use the .tar.gz you have to install it yourself.
If you want to develop / compile Java Applications you will need the JDK (Java Development Kit).