Orchestration Workflows are widely used in computational data analysis, enabling innovation and decision-making. Often the analysis components are numerous, and written by third parties, without an eye on interoperability. In addition, many competing workflow systems exist, potentially limiting portability of workflows written for any one specific workflow system. This hinders the transfer of workflows between different systems and projects, limiting their re-usability. The Common Workflow Language (CWL) project (https://www.commonwl.org/) was established in order to produce free and open standards for describing command-line tool-based workflows. The CWL language is declarative and provides a focused set of common abstractions enabling the expression of computational workflows constructed from diverse software tools. Explicit declaration of requirements for runtime environments and software containers enables portability and reuse. Workflows written according to the CWL standards are a reusable description of that analysis, runnable on a diverse set of computing environments.