Backdrop CMS

A baby dragon sits in a chair, surrounded by children's book about Drupal technologies like PHP and MySQL

From its earliest days, major version upgrades of Drupal were difficult. New versions were incompatible with previous versions, requiring lots of work to upgrade from one version to the next. But the magnitude of the change from Drupal 7 to Drupal 8 was much larger than any changes before or since. 

Backdrop CMS ( is a "fork" of Drupal -- it started with Drupal's code as it existed in 2013, just before Drupal incorporated some very large structural changes. The biggest one of these was Drupal's decision to replace the very core of the project with Symfony, an independent PHP framework. While there are some important advantages to Symfony, it's requires an entirely different way of building modules. Drupal 8 also changed the way themes are constructed, so essentially every add-on component for every Drupal site needed to be rewritten. (And to further complicate matters, the decision was made to heavily promote the use of PHP's Composer package manager, instead installing Drupal and its components directly off the server as had been done previously.) 

Backdrop not only resisted this push towards greater complexity, it built a culture devoted to serving the needs of smaller development teams, who were being left behind by Drupal. It supports much older versions of PHP and MySQL, while also supporting the latest versions. It takes great pains to make sure that add-on modules and themes continue to work, even as it adds features. It very deliberately makes decisions that make things easier and more accessible for small developers, rather than favoring large enterprise teams. And it does all this while maintaining a deep commitment to security, coordinating responses to emerging threats in close cooperation with the Drupal security team. 

Finally, because it's built on the same architecture that Drupal 7 was, migrating from Drupal 7 to Backdrop is relatively straightforward and easy, compared to migrating to recent versions of Drupal. This is good news for the hundreds of thousands of sites that have so far found the migration to recent versions of Drupal too daunting. 

In many ways, Backdrop is a comprehensive approach to simplifying Drupal.