  Within the next few years, GAIA and several instruments aiming at imag- ing
extrasolar planets will see first light. In parallel, low mass planets are
being searched around red dwarfs which offer more favourable conditions, both
for radial velocity de- tection and transit studies, than solar-type stars.
Authors of the model atmosphere code which has allowed the detection of water
vapour in the atmosphere of Hot Jupiters re- view recent advancement in
modelling the stellar to substellar transition. The revised solar oxygen
abundances and cloud model allow for the first time to reproduce the pho-
tometric and spectroscopic properties of this transition. Also presented are
highlight results of a model atmosphere grid for stars, brown dwarfs and
extrasolar planets.
