Download, Install, Update
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What is it?

Getdown (yes, it's the funky stuff) aims to provide a system for downloading and installing a collection of files on a user's machine and upgrading those files as needed. Though just any collection of files would do, Getdown is mainly intended for the distribution and maintenance of the collection of files that make up a Java application.

It was designed as a replacement for Java Web Start due to limitations in Java Web Start's architecture which are outlined in the rationale section.

Note: Getdown was designed in 2004 as an alternative to Java Web Start, because of design choices made by JWS that were problematic to the use cases its authors had. It is not a drop-in replacement for JWS, aimed to help the developers left in the lurch by the deprecation of JWS in Java 9. It may still be a viable alternative for developers looking to replace JWS, but don't expect to find feature parity with JWS.

How do I use it?

A tutorial and more detailed specification are available from the Documentation page. Questions can be posted to the OOO Libs Google group.

How does it work?

The main design and operation of Getdown is detailed on the design page. You can also browse the javadoc documentation and source code if you're interested in implementation details.

Where can I see it in action?

Getdown was originally written by developers at OOO for the deployment of their Java-based massively multiplayer games. Try out any of the following games to see it in action:

Getdown is implemented in Java, and is designed to deploy and update JVM-based applications. While it would be technically feasible to use Getdown to deploy non-JVM-based applications, it is not currently supported and it is unlikely that the overhead of bundling a JVM just to run Getdown would be worth it if the JVM were not also being used to run the target application.

Release notes

See for release notes.

Obtaining Getdown

Getdown will likely need to be integrated into your build, for which we have separate instructions. You can also download the individual jar files from Maven Central if needed:

  • In this Maven Central directory you can find the latest versions of getdown-launcher.jar (the code that updates and launches your app), getdown-ant.jar (build integration for the Ant build tool, and which can also be used with Maven), and getdown-core.jar (the core updating and launching logic which you don't usually use directly, unless you're embedding Getdown in your app).

You can also:

JVM Version Requirements

  • Getdown version 1.8.x requires Java 7 VM or newer.
  • Getdown version 1.7.x requires Java 7 VM or newer.
  • Getdown version 1.6.x requires Java 6 VM or newer.
  • Getdown version 1.5 and earlier requires Java 5 VM or newer.

Migrating from Getdown 1.7 to Getdown 1.8

See this document on the changes needed to migrate from Getdown 1.7 to 1.8.


Getdown is built with Maven in the standard ways. Invoke the following commands, for fun and profit:

% mvn compile  # builds the classes
% mvn test     # builds and runs the unit tests
% mvn package  # builds and creates jar file
% mvn install  # builds, jars and installs in your local Maven repository


Feel free to pop over to the OOO Libs Google Group to ask questions and get (and give) answers.