<tl;dr> To fix the Eclipse “No Java virtual machine was found” error, simply edit the eclipse-inst.ini file and add the -vm flag, which points it to the java utility in the JDK bin directory: ...

If you've run into common JAVA_HOME errors such as JAVA_HOME not found or JAVA_HOME set to an invalid directory, we've got the fix for you with these tips.

The answer is hidden on Apple's Java download page: "Some customers who did an upgrade install of Mac OS X v10.3 ?Panther? from Mac OS X v10.2 may have an incomplete installation of Java.