In Mountain Lion, Apple has discontinued built-in support of X11, which Spring.app relies on. Fortunately, they still support X11 development through the XQuartz project. So, in order to run Spring, you will need to download and install the latest XQuartz release.

You will find it here: http://xquartz.macosforge.org/landing/

Once you have that installed, the official Mac OS X download bundle will work fine.

If not, and you get an error saying:


Then you will need to do this:

1. Open up System Preferences
2. Go to "Security & Privacy"
3. Click on the "General" tab
4. If necessary, unlock the panel to make changes (click the lock in the bottom-left corner and then enter your account password when prompted)
5. Under "Allow applications downloaded from:" click "Anywhere"

Then you should be good to go :)

Oh, and once you've run Spring at least once, you can reset your "Allow applications downloaded from:" setting to a more restrictive option and Spring will still run. Once it is authorized it looks to be permanently so.

Belmakor