differential equations - Lyapunov Exponent

Does anyone know a (simple) Mathematica code for computing the Lyuponov Exponent for the Rossler System?

Thank you

Rossler System:

rossler = {

 x'[t] == -(y[t] + z[t]),


 y'[t] == x[t] + 0.1 y[t],

 z'[t] == 0.2 + x[t] z[t] - 5.7 z[t],

 x[0] == 1, y[0] == 1, z[0] == 1

}