J.D. Fox Micro Resource Center

Standard websites can show you lots of nicely formatted information, but are limited in interactive functionality. Java is a system that allows you to easily download and run application programs (called Java applets) through your web browser, which can greatly enhance what you can do on a website. Java applets are mostly used for connectivity related to the website you're on—such as to get technical support on an accounting program you have through the software publisher's website, use instant messaging with a sales representative through the manufacturer's website, take a 3D virtual tour of your new house on your architect's website, or use an online training system. Java-based games are also popular.

To use Java on a desktop or laptop computer, you have to download and install the Java platform software. If you visit a website that requires Java, the website will usually tell you so. The Apple iMac and MacBook, and most mobile phones and tablets, come with Java support already.

The Java platform was originally developed by Sun Microsystems (now owned by Oracle). It is also referred to as JRE (Java Runtime Environment) or JVM (Java Virtual Machine). These are all the same thing. In Microsoft Windows, you will see the white Java icon or in the system tray when a Java applet is running. If you see the orange Java icon , this means there is an update available for the Java platform software itself.

Below are links to several versions of Java, which will allow you to download the latest update for that version. Version 7 was released in 2011 to enable new features, but programs written before Java 7 may fail to run once you install Java 7 or Java 8 on your computer. So, Java 6 is still available for download, linked below. The last version of Java 6 is Update 45, and it is no longer updated by Oracle.

JavaScript is another program platform that runs on your computer from a web site, but it is completely different from Java. JavaScript enhances the interactive capabilities of a given web page, such as updating the "order total" in an online shopping cart when you add items, or giving instant feedback when you click a button on the web page, without having to reload the whole page.

Compared to Java, JavaScript is much easier for a web designer to implement, and as a result much more widely used in interactive web sites, despite being less functional. Often, a website will combine JavaScript with other players or platforms (like Adobe Flash) for enhanced functionality.

You do not need to download or install JavaScript. In fact, you can't. The ability to run JavaScript is built-in to all web browsers and enabled by default. Some users choose to disable JavaScript for security purposes, or because some websites can run really slowly when executing poorly written scripts. You can do this in the configuration screen of your web browser. If you see reference to "JScript", "VBScript", "active scripting", or even just "scripting" in any of your web browser configuration settings, this is probably referring to the JavaScript capabilities of your browser.

Because there is no way to uninstall and reinstall JavaScript (a typical diagnostic tactic), many users are frustrated when they get JavaScript error messages on a JavaScript-based web site and don't know how to try to fix it. Unfortunately, most of the time a JavaScript-based website isn't working, the problem is in the coding of the web pages themselves, which you cannot change.