The WDL specification contains all relevant information for users, developers, and engine developers. It is versioned, meaning that when a certain amount of new features are added, a new version is released. WDL versioning follows semantic versioning conventions; non-breaking changes are added in "minor version" increments (eg 1.0 to 1.1), while breaking changes are added in "major version" increments (eg 1.0 to 2.0).
The current released version is WDL 1.1.
Upcoming features which have previously been accepted but are not yet part of the latest release can be viewed as part of the development spec.
Since the release of WDL 1.0, execution engines require that every WDL file include a version statement as its first line of code, like this:
version 1.0
Note that the version statement CAN be preceded by comments.
To propose changes to the WDL specification, please read the contributions guide.