RMI Proxy Documentation (ZIP) 

RMI Proxy Documentation (online) 

RMI Proxy API (ZIP) - JAR files containing the API, freely redistributable

The RMI Replacer (modified Sun code) (ZIP)
The RMI Replacer for JDK 1.4.x (modified Sun code) (ZIP)

The RMI Replacer is a required module for the RMI Proxy product. It is a modification to Sun's RMI transport which allows you to plug in an 'object replacer'. Your Replacer is called every time an object is to be marshalled to the RMI output stream. Semantics as per ObjectOutputStream.replaceObject.  This is a free download, being modified Sun source code. Use at own risk. 

Fun stuff: 

DatagramRemoteObject: UDP Transport for RMI (ZIP) (use at own risk) 

Notes on Typesetting Computer Programs (PDF)