MD or DM? Modified dynamics at low accelerations vs dark matter
  The MOND paradigm posits a departure from standard Newtonian dynamics, and
from General Relativity, in the limit of small accelerations. The resulting
modified dynamics aim to account for the mass discrepancies in the universe
without non-baryonic dark matter. I briefly review this paradigm with its basic
tenets, and its underlying theories--nonrelativistic and
relativistic--including a novel, bimetric MOND gravity theory. I also comment
on MOND's possible connection to, and origin in, the cosmological state of the
universe at large. Some of its main predictions, achievements, and remaining
desiderata are listed. I then succinctly pit MOND against the competing
paradigm of standard dynamics with cold, dark matter. (Abridged)
