Read Dewan's Guide to understand what Sync Does. 

To run the software:

Put sync.jprops in your home directory.

Edit it to specify the machine on which the server resides,
and the server and client directories.

Put server.jprops and client.jprops in these directories,
respectively.

Put files sync.jar and swingall102.jar from the sync installation, and the
files oe4.jar shapes2.jar and swingall.jar from the user-interface
generator distribution to some library directory.
All of these files need to be in your class path.

Put the scripts to run the server and client in some directory in your path.

Edit them based on the OS you have and the name of the library directory.

Create a script to start the rmi registry. If you dont change the port number
in sync.jprops then the following command will work:
    rmiregistry 1099

Start the server on this machine using the server script.

Now you can start clients on one or more machines using the client script.

Extract the examples directory from sync.jar (using Winzip for example) to
look at the source of the applciations that come with Sync. 
Or you can extract everything from syncexamples.jar.

If you create your applications, add the directories in which they reside
to the classpaths in the server and client scripts.

Also add the model-view decomposition to *both* client.jprops and
server.jprops.