As noted on the download site, you need Java on your handheld to run this software.
Download it free from the following link.
Once downloaded, unzip the file and sync ONLY the included MIDP.prc file to your handheld, DISREGARD all other files.
http://java.sun.com/products/midp4palm/download.html
NOTE: Palm OS 3.5 or greater is required to install Java, otherwise the software will not function!