# Common Workflow Language Specifications, draft-3

The CWL specifications are divided up into several documents.

The [User Guide](UserGuide.html) provides a gentle introduction to writing CWL
command line tools and workflows.

The [Command Line Tool Description Specification](CommandLineTool.html)
specifies the document schema and execution semantics for wrapping and
executing command line tools.

The [Workflow Description Specification](Workflow.html) specifies the document
schema and execution semantics for composing workflows from components such as
command line tools and other workflows.

The
[Semantic Annotations for Linked Avro Data (SALAD) Specification](SchemaSalad.html)
specifies the preprocessing steps that must be applied when loading CWL
documents and the schema language used to write the above specifications.

If you use the CWL specifications or distribute CWL descriptions with a
publication you should [cite the standard](https://dx.doi.org/10.6084/m9.figshare.3115156.v1)