If you don't already know what OpenZDK is, see the frequently asked questions. OpenZDK is designed to be as simple for the end user as possible - while several prerequisites are required, the entire process should take no more than about 20 minutes. As OpenZDK itself is a development kit, you only need to install it if you're planning to write apps of your own rather than to install downloaded ones.
Note that “Zune SD” is used to specify all Zune models other than the Zune HD, including the Zune 30 (“Keel”), 4/8/16 (“Scorpius”), and 80/120 (“Draco”).
Answer these three simple questions to determine what you need to do next.
OpenZDK should always be used with the latest compatible firmware, currently 4.5 for the Zune HD and 3.3 for other models. You can determine your current firmware version by navigating to ABOUT, then ZUNE from the settings menu.
If you have a Zune SD, you need to run the Exploit Deployment Tool (EDT) to prepare your Zune for OpenZDK.
Warning: Do not follow the steps below if you have a Zune HD; doing so will make all 3rd-party applications unusable.
3.1.10527.100 in the Runtime drop-down.3.1.10527.100 does not appear in the dropdown, install the XNA Game Studio 3.1 Zune Extensions and restart EDT.
If you encounter problems, try rebooting your Zune and restarting EDT. Additionally, try killing the XnaTransZ.exe process using the Windows Task Manager.
To undo the operation, follow the steps above but select Unhack before deploying. This feature can also be used to recover a corrupted XNA runtime on all Zune models.
At this point, you are ready to begin installing applications. Most OpenZDK applications are available as easy-to-use DeployKit packages. If the application you are trying to install is only available in source code form, you must follow the directions for developers. Otherwise, the procedure is very simple:
Your application will now be listed under the apps (Zune HD) or games (pre-HD) menu.
If you encounter a problem, visit the Game and Hack Support forum at ZuneBoards or ask for help in #zbdf on freenode.
There is currently no central repository for OpenZDK applications, à la Cydia on the iPhone. However, all currently available OpenZDK applications are available through the Download OpenZDK Applications section at ZuneBoards.
The best way to get OpenZDK to take off is to let people know about it - so please, Digg, Stumble, e-mail, tweet, and generally spam us to all of your friends and enemies. We don't want a single Zune owner to be unaware of what OpenZDK makes possible. For more ways to get involved, visit the list of ways to contribute.
We need your help to cover hosting costs and purchase hardware for experimentation. Your donation to the ZuneBoards Development Front via the PayPal link below would be greatly appreciated. Donations are listed publically unless you specify otherwise in the message.