Oracle SQL Developer is a GUI client to connect to Oracle databases.  Oracle provide binaries for OS X, Windows and also they also offer RPM.  However, if you want to run SQL Developer on something else then you will need to click on the 'Other platforms' option when you download (and complete the annoying registration).  Here's how I got SQL Developer (3.2.2) running on Linux Mint 14.1 Cinnamon (so this should work for other distributions like Ubuntu):

sudo apt-get install openjdk-7-jdk

Then find out where the installation is.  Mine was here:

/usr/lib/jvm/java-7-openjdk-amd64

Change directory to where your SQL Developer download is and run the shell script:

./sqldeveloper

You will be prompted for the location of your JDK.  

Enter 

/usr/lib/jvm/java-7-openjdk-amd64 

or wherever your installation went.  SQL Developer will warn you about installing a later version of Java (woops) but ignoring the warning seems to get SQL Developer loading up nicely.  I've never had any issues with the wrong version of Java before so don't really care : - ).