  The Cartan development takes a Lie algebra valued 1-form satisfying the
Maurer-Cartan equation on a simply connected manifold $M$ to a smooth mapping
from $M$ into the Lie group. In this paper this is generalized to infinite
dimensional $M$ for infinite dimensional regular Lie groups. The Cartan
development is viewed as a generalization of the evolution map of a regular Lie
group. The tangent mapping of a Cartan development is identified as another
Cartan development.
