  We propose a new point of view on quantum cohomology, strongly motivated by
the work of Givental and Dubrovin, but closer to differential geometry than the
existing approaches. The central object is the D-module which "quantizes" a
commutative algebra associated to the (uncompactified) space of rational
curves. A standard loop group factorization procedure converts the D-module to
Givental's D-module and the commutative algebra to the quantum cohomology
algebra. We apply this only to the small quantum cohomology of full flag
manifolds and semi-positive toric manifolds, but even in these cases the method
is effective. In particular it gives an algorithm (requiring construction of a
Groebner basis and solution of a system of o.d.e.) for the quantum product.
