After installing Mountain Lion, I discovered Java was gone along with Subversion and Git. Even Python was partially crippled. I went through these steps to bring them back.

Git

On my machine, before the update, Git used to live in

/usr/bin/git

Which I think was a symbolic link pointing to /usr/local/git. This gets wiped out by Mountain Lion, to preserve tools using the old reference (IntelliJ IDEA in my case), I created a new sym link.

sudo ln -s /usr/local/git/bin/git /usr/bin/git

The /usr/bin folder should be on the $PATH so it should get the terminal working again too.

Subversion

Apparently, Apple removed Subversion with 10.8 so there’s nothing to do other than install it manually.

You can install Xcode which should put Subversion in /Applications/Xcode.app/Contents/Developer/usr/bin/svn. Victor Quinn talks about reinstalling Xcode to fix similar problems.

Java

OSX will install this for you the first time you try and start up a Java app. It sets up a symbolic link for mvn to point to Maven 3 which may need adjusting if you’re still using Maven 2. See this post for the fix.

Rake / Python

It even managed to mess with my Python installation which gets used when building this blog using the rake generate command. Thanks though to Sébastien Han for getting me out of it.