  We review in brief the threshold expansion, a method to perform the expansion
of Feynman integrals near the heavy quark-antiquark threshold, and its relation
to the construction of two effective theories, non-relativistic QCD (NRQCD) and
potential-NRQCD. We then summarize recent next-to-next-to-leading order results
on the decay $J/\Psi\to l^+ l^-$, the bottom quark mass from $\Upsilon$ sum
rules and the top-anti-top production cross section near threshold in $e^+ e^-$
collisions.
