Cwltool is a reference implementation of the Common Workflow Language. It provides comprehensive validation of CWL files and include tools related to working with CWL.
CWL is a specification which is used to describe command line tools and workflows, providing benefits like flexibility, scalability and portability.
Currently cwltool is developed for Linux and OS X and not for Windows Operating System.
Also, cwltool and schema-salad targets python 2.7.

The aim of this proposal is to enhance cross platform compatibility and usability of cwltool and schema-salad by:

  • Migrating to complete Python2+3 support for cwltool and schema-salad.
  • Extending cwltool support to Microsoft Windows Operating System.


Kapil kumar


  • Anton Khodak
  • Michael Crusoe
  • Janneke van der Zwaan