|MadSci Network: Computer Science|
You have run into a very common problem with Java Applets and mainstream web browsers. The only version of Java that is completely supported by Netscape and Internet Explorer is 1.02. That version was released in early 1996, more than four years ago. Since that time, several major versions have been realeased, these include 1.1, 1.2 and the current version, 1.3. Any Java applet that uses Java classes available in 1.1 or later will not work in Netscape and IE. It is true that most of the 1.1 classes are available in Netscape and IE, but not all of them.
The reasons for browser incompatibility is both economic and political. Netscape did not put enough effort in to porting 1.1 and later virtual machines into their browsers. Microsoft decided not to support the full specification because Java was developed by one of their rivals, Sun Microsystems. It is unlikely that Microsoft will ever fully support Java.
So what is a developer to do? Fortunately, there is a reliable solution to the problem. Sun Microsystems recognized the problem and released a browser plug-in that fully supports the latest versions of Java. The product is called Java Plug-in and can be found here. The plug-in is free and works with both Netscape and IE. In order to use the plug-in, your web page containing your applet must be modified to use slightly different tags. There is a converter tool available which makes the job easy.
In retrospect, Sun should not have expected third parties to properly implement Java. Sun should have just given away Java Plug-in as the only mechanism of running Java Applets in web browsers. This would have eliminated a lot of confusion among developers.
I hope this answers your question.
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