We present new grids of pre-main sequence ( PMS ) tracks for stars in the mass range 0.1 to 7.0 \mbox { M } _ { \odot } .
The computations were performed for four different metallicities ( Z =0.01 , 0.02 , 0.03 and 0.04 ) .
A fifth table has been computed for the solar composition ( Z =0.02 ) , including a moderate overshooting .
We describe the update in the physics of the Grenoble stellar evolution code which concerns mostly changes in the equation of state ( EOS ) adopting the formalism proposed by Pols et al .
( 1995 ) and in the treatment of the boundary condition .
Comparisons of our models with other grids demonstrate the validity of this EOS in the domain of very low-mass stars .
Finally , we present a new server dedicated to PMS stellar evolution which allows the determination of stellar parameters from observational data , the calculation of isochrones , the retrieval of evolutionary files and the possibility to generate graphic outputs .