The formalism of nilpotent mechanics is introduced in the Lagrangian and
Hamiltonian form. Systems are described using nilpotent, commuting coordinates
η. Necessary geometrical notions and elements of generalized differential
η-calculus are introduced. The so called s−geometry, in a special case
when it is orthogonally related to a traceless symmetric form, shows some
resemblances to the symplectic geometry. As an example of an η-system the
nilpotent oscillator is introduced and its supersymmetrization considered. It
is shown that the R-symmetry known for the Graded Superfield Oscillator (GSO)
is present also here for the supersymmetric η-system. The generalized
Poisson bracket for (η,p)-variables satisfies modified Leibniz rule and
has nontrivial Jacobiator.Comment: 23 pages, no figures. Corrected version. 2 references adde