The Earth System Modeling Framework (ESMF) project is developing a standard software platform for Earth system models. The standard defines a component architecture superstructure and a support infrastructure. The superstructure allows earth scientists to develop complex software models with numerous components in a coordinated fashion. The infrastructure allows models to run efficiently on high performance computers. It offers capabilities that are commonly needed in Earth Science applications, for example, support for a broad range of discrete grids, regridding functions, and a distributed grid class which represents the data decomposition. We illustrate these features through a simplified finite-volume atmospheric model, and report the parallel performance of the underlying ESMF components.