  A vertex operator algebra of lattice type ADE has a standard integral form
which extends a Chevalley basis for its degree 1 Lie algebra. This integral
form may be used to define a vertex algebra over a commutative ring $R$ and to
get a Chevalley group over $R$ of the same type, acting as automorphisms of
this vertex algebra. We define vertex algebras of types BCFG over a commutative
ring and certain reduced VAs, then get analogous results about automorphism
groups. In characteristics 2 and 3, there are exceptionally large automorphism
groups. A covering algebra idea of Frohardt and Griess for Lie algebras is
applied to the vertex algebra situation.
  We use integral form and covering procedures for vertex algebras to complete
the modular moonshine program of Borcherds and Ryba for proving an embedding of
the sporadic group $F_3$ in $E_8(3)$.
