Join the Drush maintainers for an overview our upcoming release - Drush 9. We've modernized every command in Drush, and changed how you author commands. This 10 year project can still run! Learn more about:

Composer-centric point of view
Converting from a Drush Make site.
The new Drush launcher
Writing Annotated Commands
Output Formatters
Configuration techniques like config_split project and the config-pull command.
More details about these changes can be found on our roadmap.