  We present a new approach to far-from-equilibrium statistical mechanics,
based on the concept of generalized entropy, which is a microscopically-defined
generalization of Onsager-Machlup functional. In the case when a set of slow
(adiabatic) variables can be chosen, our formalism yields a general form of the
macroscopic evolution law (Generalized Langevin Equation) and extends
Fluctuation Dissipative Theorem. It also provides for a simple understanding of
recently-discovered Fluctuation Theorem
