mod_pagespeed available for RPM based and Debain based Linux distributions. I am going to show you how to install this module in Ubuntu.
Go to mod_speed download page and download .deb package according to your platform. Save file on your desktop or home folder.
Right click on your .deb package file and select “Open with GDebi Package Installer”
On the next screen, Installer dialog box will open. Click on “Install Package” button top right corner to begin installation. Wait until installation finished.
Once installation finished, restart Apache to load mod_pagespeed module.
Open “Terminal Window” and run following command to restart apache.