  This contribution reviews a number of applications of the ab initio no-core
shell model (NCSM) within nuclear physics and beyond. We will highlight a
nuclear-structure study of the A = 12 isobar using a chiral NN + 3NF
interaction. In the spirit of this workshop we will also mention the new
development of the NCSM formalism to describe open channels and to approach the
problem of nuclear reactions. Finally, we will illustrate the universality of
the many-body problem by presenting the recent adaptation of the NCSM
effective-interaction approach to study the many-boson problem in an external
trapping potential with short-range interactions.
