How do you check the current version of eclipse that I am currently running? Is it possible to tell if it is aqua or carbon (I am running Mac OS X 10.5)?
There is a system property eclipse.buildId (for example, for Eclipse Luna, I have 4.4.1.M20140925-0400 as a value there).
I'm not sure in which version of Eclipse did this property become available.
Also, dive right in and explore all the available system properties -- there is quite a bit of information available under eclipse.*, os.* osgi.* and org.osgi.* namespaces.
Eclipse Menu -> About Eclipse SDK
On my mac it took me a while, but it is actually easy.