From CyberWurx Customer Wiki

Enable Bukkit

To enable bukkit, log into your gamepanel account and view your minecraft server's server details. On the left hand side you will see Bukkit and a text box with either 1 or 0 inside.

Boolean value guide:

0 - Disabled
1 - Enabled
2 - Snapshot Build Enabled

Set this value to either 1 or 0 depending on if you want to enable or disable bukkit. Make sure you restart your server to apply the changes.

*New!*

You can optionally use the snapshot build of bukkit by setting bukkit to 2.