A work flow package that enables users to run a large number of programs
(with dependencies on each other and on time) in a controlled environment.
It provides tolerance for hardware and software failures, combined with good
restart capabilities. It is used at ECMWF to run all our operational suites
across a range of platforms.

ecFlow submits tasks (jobs) and receives acknowledgements from tasks when they
change status and when they send events. It does this using using child commands
embedded in the scripts. ecFlow stores the relationship between tasks and is
able to submit tasks dependent on triggers.