chocolate-doom software package provides Doom engine closely-compatible with vanilla 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 chocolate-doom
chocolate-doom is installed in your system.
Make ensure the chocolate-doom package were installed using the commands given below,
$ sudo dpkg-query -l | grep chocolate-doom *
You will get with chocolate-doom package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Games |
| Package | chocolate-doom |
| Version | 2.0.0-1ubuntu1 |
| Description | Doom engine closely-compatible with vanilla doom |
| Sub Section | Games |