We describe the capabilities of the \code{pyutilib.workflow} software package.
This package provides Python classes that provide an intuitive interface
for defining and executing scientific workflows.  Further, \code{pyutilib.workflow}
is a native Python package, so it can be used to define workflows within
Python software applications.  Additionally, \code{pyutilib.workflow} includes a utility
for creating a command-line driver that execute workflows as subcommands of a command-line script.
