Mostly some cleanup... First, this tries to keep the versioning separated from the rest of the Makefile. I used the "foo := $(foo) bar" syntax rather than "foo += bar" as I think the += is not available on all versions of make. Moreover, I replaced "$(LIBCDIO_LIBS)" with "libcdio.la" as "$(LIBCDIO_LIBS)" is "../lib/libcdio.la". That make a difference if you try to build libiso9660.la while libcdio.la is not available. Make knows how to make libcdio.la but not ../lib/libcdio.la.