bspwm software package provides Binary space partitioning window manager, 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 bspwm
bspwm is installed in your system.
Make ensure the bspwm package were installed using the commands given below,
$ sudo dpkg-query -l | grep bspwm *
You will get with bspwm package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | X Window System software |
| Package | bspwm |
| Version | 0.9.2-1 |
| Description | Binary space partitioning window manager |
| Sub Section | x11 |