...For installation, just install Java, download the je.jar file, and start the program with "java -jar java.jar" on a command line. For more easy use, create a batch file on your system containing something like "javaw -jar java.jar %1" (Windows syntax shown).
The editor will create backups by default, and you can set a backup directory. It creates a .je.cfg configuration file in your home directory for the settings.