Jython 2.5 and 2.2.1 are distributed as executable jar file installers. After downloading it, either double click the jython_installer-2.5.0.jar or run java with the -jar option
java -jar jython_installer-2.5.0.jar
This will start the regular GUI installer on most systems, or a console installer on headless systems. To force the installer to work in headless mode invoke the installer as:
java -jar jython_installer-2.5.0.jar --console
The installer will then walk through a similar set of steps in graphical or console mode: showing the license, selecting an install directory and JVM and actually copying Jython to the filesystem. After this completes, Jython is installed in the directory you selected. Executing a script in the install directory, jython on Unix-like systems or jython.bat on Windows, will start up the Jython console, which can be used to dynamically explore Jython and the Java runtime, or to run Jython scripts.
The standalone option does no caching and so avoids the startup overhead (most likely at the cost of some speed in calling Java classes, but I have not profiled it)
You can try it out by running the installer:
$ java -jar jython_installer-2.5.0.jar
then when you come to the "Installation type" page, select "Standalone".
The installation will generate a jython.jar with the Python standard library (/Lib) files included, which can be run as:
$ java -jar jython.jar
Of course you can run scripts just by calling them as you might expect:
$ java -jar jython.jar script.py
Or, add this file to the classpath of your application.
You can get a list of installer options (to install Jython unattended, for example) by running:
$ java -jar jython_installer-2.5.0.jar --help