Basic Information

This section covers the following topics:

Basic Information

Q: What is Java Plug-in Software?

A: Java Plug-in Software is a software product from Sun Microsystems, Inc., that allows enterprise web managers to direct Java applets and JavaBeansTM components on their intranet web pages to run using Sun's Java Runtime Environment (JRE). With the 1.4 release of Java Plug-in, it is also allows the conventional APPLET tag to direct Java applets to use Sun's JRE. This is especially useful in browser, such Internet Explorer 6, that do not support Java.

Q: For whom is Java Plug-in Software intended?

A: Java Plug-in Software is designed for enterprise customers who want to deploy Java 2 SDK, Standard Edition based applets on their intranet web pages, and support Microsoft Windows-, Solaris-, and Linux-based browsers in their enterprise. With the 1.4 release, it is also designed for the consumer who wants to run Java applets on a web page.

Q: Is there documentation available for Java Plug-in Software?

A: To assist in your deployment of Java Plug-in Software, Sun has made available a variety of technical documentation. Documentation regarding the HTML specifications, using Java Plug-in Software in intranet environments, how proxy configuration works, how to script applets, and much more are available from the Java Plug-in Software documentation page. For the consumer-oriented product that uses conventional APPLET tag support, you may also want to visit the Get Java Technology page and see the documentation available there.

Q: What features does Java Plug-in Software offer?

A: Java Plug-in Software delivers several key capabilities to for users of Internet Explorer or Netscape's Navigator:

Q: What is the advantage of downloading and using Java Plug-in Software rather than the browser's default JavaTM virtual machine?

A: Using Java Plug-in Software allows enterprises and consumers to:

  1. Take full advantage of Java 2 SDK, Standard Edition functionality such as JavaBeans, JNITM, and RMI today.
  2. Develop and deploy 100% Pure JavaSM applets on Internet Explorer and Netscape Navigator browsers, and be assured that they will run reliably and consistently in both browsers.
  3. Be assured that they will receive support for the latest releases of Sun's Java 2 platform --including the high-performance Java HotSpotTM virtual machine--in Internet Explorer and Navigator as soon as Sun releases them.
  4. Run applets in web browsers that no longer support Java.

Q: Is Java Plug-in Software included in the Java 2 Software Development Kit (SDK), Standard Edition?

A: Yes.

Q: Does Java Plug-in Software work on platforms other than Microsoft Windows or Solaris (for example, Mac OS, AIX, Linux, HP-UX, etc.) versions of IE or Navigator?

A: Sun has made Java Plug-in Software available for porting to all operating system providers. For information about support for Java Plug-in Software on other operating systems, contact the operating system provider.

Q: What information should I provide when reporting a bug to

A: When reporting bugs against Java Plug-in Software, always include the following information:

  1. Operating system, including version number
  2. Web browser, including version number
  3. Complete output of the JavaTM Console window
  4. Network configuration information—proxy, special intranet environment, etc.
  5. Complete description of the failure/problem encountered. Include the steps required to reproduce the problem.

Supported Features

Q: Does Java Plug-in Software offer support for all the features in Java 2 SDK, Standard Edition?

A: Yes. Java Plug-in Software uses the same JRE that users can download from Sun's web site today (see

Q: Is Java Plug-in Software fully compliant with the JCK (Java Compatibility Kit) test suite for Java 2 SDK, Standard Edition?

A: Java Plug-in Software is fully compliant with the JCK test suite for Java 2 SDK, Standard Edition.

Q: What browsers and operating systems does Java Plug-in support? 

A: See Supported Operating Systems and Browsers.

Q: Does Java Plug-in Software support scripting? 

A: Java Plug-in Software supports scripting of applets in Internet Explorer and Netscape 6. However, scripting is not available when using Java Plug-in Software in Navigator 4.

Q: Does Java Plug-in Software support signed applets?

A: Yes, Java Plug-in Software supports standard Java 2 SDK, Standard Edition signed JARs and applets signed using Netscape signing tools. See the How to Sign Applets Using RSA-Signed Certificates for more details.

Q: Does Java Plug-in Software automatically recognize and use the proxy server configuration that the browser was using?

A: It can. There are in fact three options beginning with the 1.4 release. See Proxy Configuration for details.

Q: What protocol does Java Plug-in Software support over the proxy?

A: HTTP, HTTPS, FTP, Gopher, and SOCKS are supported.

Q: Does Java Plug-in Software support SSL?

A: Yes, SSL is supported through Java Secure Socket Extension (JSSE).

Q: Is there a way to pre-load Java Plug-in Software during the browser startup?

A: Internet Explorer and Netscape Navigator do not have mechanisms to support pre-loading Java Plug-in Software during startup. You can work around this limitation by providing your own startup page that launches a dummy applet using Java Plug-in Software.

Q: Can I set up Java Plug-in Software to download from an intranet web server (behind a firewall) rather than from Sun's web site? 

A: Yes. For more information, see Intranet With OBJECT/EMBED Tag under Part II: Deployment Schemes.

Q: How can I open the Java Plug-in Control Panel on Microsoft Windows? 

A: On the Start menu, choose Start>Settings>Control Panel, then double-click on the steaming Java cup icon labeled Java Plug-in.

Version Information

Q: How can I tell what version of Java Plug-in Software has been installed?

A: There are a couple of ways:

Q: Can different versions of Java Plug-in Software co-exist on the same system?

A: Yes, it can be done through multi-version support. See Supporting Multiple Versions of JRE/Java Plug-in.