I recently encountered an issue where I was unable to add a JVM to my Eclipse install on Snow Leopard. There was no MacOS X VM option under Installed JREs -> Add and attempting to use the Standard VM resulted in an error. After digging around in Eclipse bug reports, I discovered this is a known issue with the Cocoa build of Galileo with PDT pre-installed. The easy fix is to install Eclipse without PDT (just install the Eclipse IDE for Java - Cocoa 64 bit) and add PDT plugin later. When you take this route, the MacOS X VM will be configured automagically.