maven compile java version

[ChadDavis]

In eclipse, with the m2eclipse plugin, my Jackrabbit 1.6 source won't
compile.  It failing to recognize "assert" and other java version
related things.  From the command line, I can build the project fine.
But I wonder where the java version settings are?  Doesn't maven use
Java 1.3 by default?  Where is the project defining a higher version
of Java?  I can't find it.