The Smalltalk/X system from Claus Gittinger has a Smalltalk/Java
integration. The system uses a dual interpreter to use Java 

The class hierarchy looks like the following:

Object
 Behavior
  ClassDescription
   Class
    JavaClass
     java.lang.Object class

Object
 JavaObject
  java.lang.Object
   ...(more Java classes)

At this time he supports JDK1.1.x. With this integration he can
debug, browse, inspect java objects in his Smalltalk tools and run 
Java applets in Smalltalk Windows, ...
Native java calls are delegated to a special JavaVM class 
implementing the functionality in Smalltalk.
To get more informations look at: http://www.exept.de/en/stja97.html
Smalltalk/X also provides a STC (Smalltalk to C compiler).




-Torsten