What does Java do and is it necessary?

I'm looking for a little education here. A How To article on disabling Java in the recent Mac Life indicates Java can be an malware vector to OS X. I am looking for a brief understanding of what Java is and what it does, and more importantly is it really necessary to be enabled?

1st, if you have installed all the latest Mac OS X Lion (or Snow Leopard, or Leopard) updates, the known Java flaw has been fixed. If you have not applied all the updates, you should do it as soon as possible.

You can disable it, either just in your browser or entirelly if you like. If something doesn't run, it will ask for Java to be installed and you will know that you might need it for that 3rd party application.

The Flashback malware gained access via the web browser Java plug-in, so just disabling that is also good enough, but also redundent if you have applied all the latest Mac OS X updates.

I understand it is an interpretive programming language that runs graphics on websites. Is that all it is/does?

Java is a complete programming environment developed by Sun Microsystems (Sun is now owned by Oracle).

It is commonly used to write applications that run on multiple platforms with little or no changes. This is why it is popular as most Java developers do not need to worry if the system is Mac, Windows, Unix, etc... It is also used in some Smart Phones, Set Top TV boxes, dedicated black box electronics, etc...

On the Mac some (but not very many) web sites use Java for complex web site interactions, such as a game you run from a web site. However, this is very rare and you are unlikely to run into one of these web sites, so disabling your browser's Java plug-in is generally not a problem.

Where does java Script fit in?

JavaScript is a totally different language and programming environment that was created about the time Java was the "Cool Kid" in town, so the JavaScript developers stole the name. They are not really related.

One of the reasons very few web sites depend on Java is because they can do most of what they need via straight HTML or HTML and JavaScript.

So you DO WANT JavaScript enabled, or that will impact your web browsing experience.

Lastly, by disabling it on my Mac and in my browsers, will websites just not work?

Again, few web sites use Java, so disabling the Java plug-in within your browser's preferences is generally an OK thing to do.

However, you may have some applications written in Java that you use on yoru Mac where disabling Java via the Applications -> Utilities -> Java Preferences may (or may not) affect running some apps on your Mac. For example, if you use CrashPlan (backup utility) it is written in Java.

But so far, Java based applications have not been a malware problem. Only the Java browser plug-in.

You can find that information, along with more information about the Flashback malware, at About the Flashback malware. Note that JavaScript and Java are completely different things, despite the similarity in names.

(Note that my pages contain links to other pages that promote my services, and this should not be taken as an endorsement of my services by Apple.)

DesertRatR wrote:

I am looking for a brief understanding of what Java is and what it does, and more importantly is it really necessary to be enabled?

Java is an old programming language and runtime that was invented in the early '90s with the intention of taking over the programming world. It was a miserable failure. The only people that use it today are enterprise consultants. They use it because it is miserable and they charge by the hour. If they used any other tool, they would get done sooner and make less money. Java it is.

It is not necessary to be enabled unless you have some junky enterprise software that you have to use for work. What is enterprise software you ask? Enterprise software is any software that costs more for your house and is so buggy you would never use it on your own machine unless forced to. Governments love enterprise software.

I understand it is an interpretive programming language that runs graphics on websites. Is that all it is/does?

It doesn't even do that. One of the vectors for taking over the computer world were Java applets. Java was also going to take over the newly-created world wide web. Applets were an even greater feilure. Not even enterprise customers use it anymore. Java applets had one, primary, critical security promise - that web sites would be isolated from users' machines and post no malware threat. It turns out that promise was broken from day one. Are you detecting a theme there?

Where does java Script fit in? Lastly, by disabling it on my Mac and in my browsers, will websites just not work?

Javascript is just an unfortunate name. It has nothing to do with Java. The name was coined back in the days when people thought Java was going to take over the world. Java was a colossal failure. Javascript is pretty neat.

BTW, I use Intego's anti-malware suite.

I'm sorry to hear that. My condolences. Did I mention how enterprise customers love anti-virus software? It slows everything down and raises support costs. When the taxpayer is footing the bill, that's all good. Mac users installing anti-virus is like homeowners installing $ 800 toilet seats.