  We review the recent attempts of unifying inflation with quintessence. It
appears natural to join the two ends in the framework of brane world cosmology.
The models of quintessential inflation belong to the class of {\it
non-oscillatory} models for which the mechanism of conventional reheating does
not work. Reheating through gravitational particle production is inefficient
and leads to the excessive production of relic gravity waves which results in
the violation of nucleosynthesis constraint. The mechanism of {\it instant
preheating} is quite efficient and is suitable for brane world quintessential
inflation. The model is shown to be free from the problem of excessive
production of gravity waves. The prospects of Gauss-Bonnet brane world
inflation are also briefly indicated.
