The evidence for dark matter is overwhelming from cosmological observations at small and large
scales. Yet, its existence is inferred indirectly, through its gravitational effects, but its nature is
still unknown. Among the preferred dark matter particle candidates are new particles beyond
the standard model with weak scale interaction with the known particles and mass in the GeV
to hundreds of GeV scale. They are generically called Weakly Interacting Massive Particles
(WIMPs). Thanks to their (weak but not zero) coupling with ordinary matter, they can be detected
with a particle detector in the Earth. I will review the concepts of direct detection of WIMPs and
the main experimental efforts to search for them, including the only positive result up to date
(DAMA/LIBRA) and the ongoing experiments attempting to confirm or refute this signal in a
model independent way. I will also discuss future experiments, and their ability to explore new
regions of the WIMPs parameter space or go beyond the current ultimate limits.