I know this is probably a horrendously n00b question.
but what is eagle libraries??
Files that contain footprints of parts for pcb layouts using Eagle cad software.
Since there are millions of parts, and many new ones come out often, all cad tools have some sort of library system. Users can add new ones (and they do). Some, like Eagle and FreePcb save these as ordinary files, which users can share.
will eagle libraries work with altium designer 6?
The Pulsonix software I use can import Eagle designs and libraries, perhaps Altium can.