Making an educated guess, I would say that not many of you have or need Java on your computer.
Java falls into that troubling category of what I call “helper applications”. Flash is also part of this category. You do not interface with Java (or Flash) directly but it may be needed on your computer to help run other applications.
Let me step back and give a little history. Java is a programming environment. If a small company were writing a software application for both Mac and Windows and they didn’t want or (or have the resources to) write a uniquely tailored application for each environment, writing it on Java could make a lot of sense.
On Windows, Java is a separate application that is downloaded from Java.com. On the Mac, Java was included for many years. Recently that has not been the case. Mac users needing Java will also need to grab it from Java.com. On both operating systems, Java should notify you of updates. Those updates are very important. Computers with out of date versions of Java are susceptible to attack.
However, I wanted to alert you to a more covert way that Java could mess with your computer. Oracle publishes Java and they think that they should be able to make a little money on this utility that 10’s of millions of people use for free. For years, Java has been bundling the Ask Toolbar (or other useless junk) with the Windows version of Java. Fortunately, the Mac version of Java has stayed clean. That changed as of the beginning of March.
This brief guide will show you how to suppress Java sponsor notifications when you update Java (Mac and Windows).
You may use some specific applications that require Java. As far as I know the only one requiring Java that I regularly recommend to clients is Crash Plan backup software. Crash Plan is a competitor of Carbonite. I generally recommend Crash Plan for families because you can backup an unlimited amount of data on up to 10 computers for about $150 per year. If you use Crash Plan, you will need to keep Java up to date.