CentOS comes with OpenJava JRE installed. However that doesn't provide the required libraries to run Java from browsers (read: applets). Here are the steps to install and enable applets / Java plugin in Firefox browser on CentOS 5. Note: The instructions may be applicable to other versions of CentOS, Fedora, others Linux distros too. However it has only been tested on CentOS 5.3.

I never thought I would have to write this article. Downloading Java was the simplest thing possible. Just go to java.sun.com and download the JDK. Unfortunately Sun has (intentionally?) complicated the procedure to such an extent that it almost takes an expert to download the proper version of JDK and without any extra and often unnecessary baggage. Let's call this article: The Art of Downloading & Installing JDK 6