Sun provides the
Java Plugin for (among other things) COM/ActiveX
integration. As far as I can tell with an initial look, the
integration provided is making a Java class (or maybe only a
Java Bean?) callable as a COM object. It does not seem to
provide a way to call COM objects from Java. (If this is wrong,
please let me know.)
JWindows
provides Java integration of the Win32 API.
Server Stuff
The Java Apache Project
integrates Java with the Apache Web Server.
There are a number of sub-projects, of which the
Apache JServ Java
Servlet engine is probably the key. Now obsolete, and
superceded by ... (see next)
Jakarta is another
Apache-Java project, to provide a next-generation servlet
engine (code-named Tomcat) plus Java Server Pages (JSP).
Cocoon is
a Java Servlet-based engine for providing server-side XML
transformations via XSL. It is very nice.