Language Support

Below are the Domain Specific Languages (DSL) that Cromwell currently supports and will soon support for describing your workflow.

Current Language Support

WDL Draft 2

Cromwell started life as a WDL engine and WDL draft2 was our first language! For many examples on how to use WDL and some great getting-started resources you can view the OpenWDL site.

Cromwell supports the majority of Draft-2 of the WDL Spec.

Known Issues:

  • Be careful when using Object. They are superceded by 'struct' in WDL 1.0 and are being removed outright in WDL 2.0.
  • Cromwell does not support nested scatters in draft-2.

WDL 1.0

Cromwell also supports WDL version 1.0.

As well as the changes to the WDL spec between draft-2 and 1.0, Cromwell also supports nested scatters and the localization_optional optimization in WDL 1.0.

Future Language Support

WDL 'development'

As the SPEC is being improved and honed, Cromwell continues to support the current development version of WDL. That means that when (or shortly after) new versions are published, Cromwell will be ready to support them.