drupal7 software package provides fully-featured content management framework, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install drupal7
drupal7 is installed in your system.
Make ensure the drupal7 package were installed using the commands given below,
$ sudo dpkg-query -l | grep drupal7 *
You will get with drupal7 package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Web Software |
| Package | drupal7 |
| Version | 7.50-2 |
| Description | fully-featured content management framework |
| Sub Section | Web |