  A pulsar-like compact star is the rump left behind after a supernova where
normal baryonic matter is intensely compressed by gravity, but the real state
of such compressed baryonic matter is still not well understood because of the
non-perturbative nature of the fundamental color interaction. We argue that
pulsars could be of condensed matter of quark clusters, i.e., "quark-cluster
stars" which distinguish from conventional neutron and quark stars. In
comparison with 2-flavour symmetric micro-nuclei, a quark-cluster star could
simply be considered as a macro-nucleus with 3-flavour symmetry. New research
achievements both theoretical and observational are briefly presented.
