freedm software package provides multiplayer-oriented maps for Doom, 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 freedm
freedm is installed in your system.
Make ensure the freedm package were installed using the commands given below,
$ sudo dpkg-query -l | grep freedm *
You will get with freedm package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Games |
| Package | freedm |
| Version | 0.8-1 |
| Description | multiplayer-oriented maps for Doom |
| Sub Section | Games |