Cylc is a general purpose workflow engine that also orchestrates cycling systems very efficiently. It is used in production weather, climate, and environmental forecasting on HPC, but is not specialized to those domains.

Cylc is an active Open Source project on GitHub.
See Cylc Publications and Reports below.

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Cylc Does Cycling Properly

Cylc unwinds the cycle loop to get a dependency graph with no barrier between cycles. This allows interleaved cycles for:

  • Fast catch-up from delays
  • Sustained high throughput off the clock
  • Seamless transitions between fast catch-up and clock-limited real-time scheduling

Why Use Cylc?

Production Ready Scaling Powerful UIs Ease of Use Multi-User Installations Advanced Scheduling Resilience

Publications and Reports

If you use Cylc please cite it in your publications and let us know if your site can be listed on this website.

Workflow Automation for Cycling Systems: The Cylc Workflow Engine
H. Oliver et al
Computing in Science & Engineering Vol 21, Issue 4, July/Aug 2019. DOI: 10.1109/MCSE.2019.2906593
DOI: 10.1109/MCSE.2019.2906593 DOI 10.1109/MCSE.2019.2906593

Cylc: A Workflow Engine for Cycling Systems
Oliver et al., (2018).
Journal of Open Source Software, 3(27), 737. DOI: 10.21105/joss.00737

Citable DOI for Cylc code releases.

Old (2017): Cylc response to Assessment Report on Autosubmit, Cylc and ecFlow