AbstractLet k be an arbitrary field of characteristic 0. It is shown that for any n⩾1 the universal enveloping algebras of the Poisson symplectic algebra Pn(k) and the Weyl algebra An(k) are isomorphic and the canonical isomorphism between them easily leads to the Moyal product. A basis of the universal enveloping algebra Pe of a free Poisson algebra P=k{x1,…,xn} is constructed and it is proved that the left dependence of a finite number of elements of Pe over Pe is algorithmically recognizable. We describe the Poisson dependence of any two elements of a free Poisson algebra in characteristic 0 in the language of universal derivatives. The Fox derivatives on free Poisson algebras are defined and it is proved that an analogue of the Jacobian...