mwm software package provides Motif Window Manager, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install mwm
mwm is installed in your system.
Make ensure the mwm package were installed using the commands given below,
$ sudo dpkg-query -l | grep mwm *
You will get with mwm package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | X Window System software |
| Package | mwm |
| Version | 2.3.4-5 |
| Description | Motif Window Manager |
| Sub Section | x11 |