  We review our current knowledge on the IMF in nearby environments, massive
star forming regions, super star clusters, starbursts and alike objects from
studies of integrated light, and discuss the various techniques used to
constrain the IMF.
  In most cases, including UV-optical studies of stellar features and
optical-IR analysis of nebular emission, the data is found to be compatible
with a "universal" Salpeter-like IMF with a high upper mass cut-off over a
large metallicity range.
  In contrast, near-IR observations of nuclear starbursts and LIRG show
indications of a lower M_up and/or a steeper IMF slope, for which no alternate
explanation has yet been found. Also, dynamical mass measurements of seven
super star clusters provide so far no simple picture of the IMF.
  Finally we present recent results of a direct stellar probe of the upper end
of the IMF in metal-rich HII regions, showing no deficiency of massive stars at
high metallicity, and determining a lower limit on M_up of >~ 60--90 Msun.
