Java applets are different from the other interfaces in that they are run directly from your browser. Use a java applet if you just want a quick game without installing anything.
Jin Applet: a full-featured interface with no installation needed
The Jin Applet by Alexander Maryanovsky is by far the fanciest of the applet interfaces. You can customize the font, chessboard and so forth, and it will save your preferences on the central server, so that wherever you go, be it an Internet Cafe, a public library or a friend's house, your preferences go with you. You can also download and install Jin as a Java application, see just below.
Java applications are downloaded and installed like any other program. They are a good option if you can't use a regular client or want to use the same client on more than one operating system.
Jin by Alexander Maryanovsky is a full-featured Java application interface for ICC.
Note: In order to run the Jin application you need a Java Runtime Environment. If you do not already have it installed, you may obtain it from one of the following sources: