When the two elements are combined - no.
Software side is free, the assets no. You cannot re-distrubute the entire
package as is.
In this case it is your own personal choice if you choose to use the combo,
if you are ok with not sharing everything then that is your own call. That
where free software comes in, it isn't so much a 'specification' as such but
more a set of goal that you should strive for.
This is an issue that I find very interesting in that it combined both the
concepts of the free software movement and the free arts movement. They are
very similar in their goals but different in the details.
