- Converting modules to Backdrop from Drupal 7 (official documentation)
- Porting a Module to Backdrop – Basics (YouTube video by Backdrop co-founder Nate Haug a.k.a. quicksketch)
- Backdrop change records (official list of important changes from Drupal 7)
- Instructions for applying to the Backdrop contributed project group on GitHub
- Backdrop core repository on GitHub
- Main Backdrop CMS site (including links to download the code or spin up an automatic Backdrop demo site)
- Backdrop CMS: Setting The Record Straight (recent Drupal Watchdog article by Backdrop co-founders Jen Lampton and Nate Haug)
- How to Maintain Contrib Modules for Drupal and Backdrop at the Same Time Part 1, 2, 3
- Backdrop CMS – Setting The Record Straight