As you probably know, the Unity notification area (systray) whitelist is no longer available in Ubuntu 13.04 so you can't whitelist applications to be able to use the systray. If you can't live without an application that still uses the old notification area, here's how to get the Unity systray whitelist back in Ubuntu (Unity).
- Update 1: the PPA is now also available for Ubuntu 13.10.
- Update 2: The packages in this PPA no longer restore the systray whitelist which used to allow whitelisting individual applications to be able to use the systray. Instead, the packages in this PPA whitelist all systray applications now!
- Update 3: the PPA now also works with Ubuntu 14.04 LTS.
Java and Wine applications have been hard-coded and continue to show up in the notification area but there are still some applications that don't have an AppIndicator and thus, can't use the systray. Some of the popular apps that can't use the systray anymore in Ubuntu 13.04 include: Truecrypt, Cryptkeeper, Blueproximity, Pidgin (if you don't want to use the Messaging Menu) and KeePassX (although KeePassX from the Ubuntu 13.04 repositories has the systray disabled in its settings and it can be enabled so for it you'll have to either use a PPA or build it from source).
How to whitelist all systray apps in Ubuntu 14.04, 13.10 or 13.04 (with Unity)
If you want all the applications that use a tray icon to be able to make use of it in Ubuntu 14.04, 13.10 or 13.04, you can use a PPA that comes with Unity patched to re-enable the systray whitelist. To do this, open a terminal and run the following commands:
sudo add-apt-repository ppa:timekiller/unity-systrayfix sudo apt-get update sudo apt-get upgrade
Then, restart Unity by pressing ALT + F2 and entering "unity" or by logging out. The PPA now automatically whitelists all applications so there's no need to manually whitelist individual apps to be able to use the systray.
How to revert the changes
If you want to revert the changes and go back to the default Unity packages from the Ubuntu repositories, use the commands below to purge the Unity systray whitelist PPA:
Then, restart Unity or log out and log back in.
sudo apt-get install ppa-purge sudo ppa-purge ppa:timekiller/unity-systrayfix