For almost three decades ECMWF used SMS (Supervisor Monitoring Scheduler) package to control the work flow for the Centre's operational models and systems. Written at ECMWF, it allows the design, submission and monitoring of jobs both in the Research and Operations Departments, and provides common tools for scientists, analysts and operators to cooperate. A large number of organisations also use SMS (from both Member and non-Member States). Development of SMS has now stopped. Support for SMS is only on the currently tested computer platforms, not on any new ones.

The replacement, ecFlow, has superseded SMS. It is a complete rewrite using object oriented methodology and modern standardised components; it acts as a comprehensive replacement for SMS. The rewrite helps improve maintainability, allows easier modification and introduces object orientated features. The proprietary script language used by SMS, CDP, have been replaced by Python.
ecFlow is licensed under the Apache License, Version 2.0. 

You can find an introduction to ecFlow in the ECMWF Newsletter article  (Autumn 2011), starting at page 30.