Marvin Applet Platforms

Built-in JVM in the browser

Most of the (Java capable) browsers does not includes a built-in JVM (Java Virtual Machine). browsers require an installed JRE (Java Runtime Environment) for running applets. Each (Java capable) browser can launch applets with the installed JRE by the help of a Java Plugin. Normally, Java Plugins are part of the JRE and do not require any manually settings to be able to run applets. (In the documentation of your browser, you can find more info about its installation.)
The following browsers include built-in Java:
 
built-in JVM
Netscape 6.x - 7.0
Java 2 (including Swing)
Netscape 4.7x - 4.8
Sun's Java 1.1 compatible
Netscape 4.0 - 4.05
Sun's Java 1.0 compatible
Netscape 4.x for Macintosh
Sun's Java 1.1 compatible1
Internet Explorer
Sun's Java 1.1 compatible

1: These built-in JVMs still use the 1.0 version of the AWT package.

The "marvin.js" interface can detect the best configuration for the Marvin applets on the current platform (tries to use the Swing version with the proper JVM if Swing is supported). But you can set the prefered JVM by using the "jvm" parameter. (The first MarvinSketch example demonstrates its usage.) Actually, "marvin.js" operates with APPLET, OBJECT and EMBED tags. The following document can be useful for you if you would like understand what is the difference between the above tags: Encountering OBJECT, EMBED, and APPLET Tags With Different Plug-in Versions and Browsers

Marvin/Swing

Our swing applets are signed by Thawte's Java Code Signing Certificate which uses a JDK 1.3 code signing tool. Applets signed by this tool support browsers that contain JDK 1.3 or later (including Swing).

 
Signed applets
Netscape 4.x
yes*
Netscape 6.x, 7.x
yes
MS Explorer 4.x
no
MS Explorer 5.x, 6.x
yes
Mac OS 8.x, 9.x
no
all Java enabled browsers in Mac OS X
yes**

*: Netscape 4.x can use Java 1.3 and Swing with Java Plugin, but in this case applet methods cannot be accessed from JavaScript (see Java - JavaScript communication).
**: Limitations under OS X. (see Notes for Mac users)

Swing applets can be accessed in two ways:

Java - JavaScript communication

In a few browsers, especially early version of Netscape and the OS X versions of Internet Explorer, the plugin interface does not support Java - JavaScript communication.

 
calling Java
from JavaScript
calling JavaScript
from Java
Netscape 7.01 -
yes
yes (MAYSCRIPT)1
Netscape 6.x, 7.0
yes
yes (MAYSCRIPT)1,2
Netscape 4.x
no
yes (MAYSCRIPT)
MS Explorer for Windows
yes
yes
MS Explorer for Machintosh systems
no
no

1: Limitations under OS X. (see Notes for Mac users)
2: Under Linux, the browser may crash when a signed applet calls JavaScript from Java.

In Netscape 6 and later versions (if Java Plug-in 1.3.1_01a or later is installed) the applet will be run by the installed plug-in even in built-in mode (APPLET tag). In that case in Netscape 6.x, there are no problem with Java - JavaScript communication unless using the EMBED tag.