Do you receive this message?
A Java Runtime Environment (JRE) or Java Development Kit (JDK) must be available in order to run Eclipse
No Java virtual machine was found after searching the following location
Home/jre/bin/java
Java in your current PATH
Solution
In the Eclipse.app/Contents/MacOS/eclipse.ini file put
-vm /System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home/bin/java
right before
-vmargs
Pay attention, the carriage return is important after “-vm”
Remaining issue
On my computer, after installing aptana studio 3 (http://www.aptana.com), the Eclipse.app/Contents/MacOS/eclipse.ini was overwritten and I had to update the file again
Source: http://stackoverflow.com/questions/5898111/eclipse-not-working-no-java-virtual-machine-was-found