firefox-dev software package provides Safe and easy web browser from Mozilla - development files, 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 firefox-dev
firefox-dev is installed in your system.
Make ensure the firefox-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep firefox-dev *
You will get with firefox-dev package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Development |
| Package | firefox-dev |
| Version | 50.0+build2-0ubuntu0.14.04.2 [ |
| Description | Safe and easy web browser from Mozilla - development files |
| Sub Section | devel |