Development and Evaluation Installations
Alfresco provides a number of different installers for different operating systems and platforms. However, these installers are not recommended for production environments.
https://sourceforge.net/projects/alfresco - more Alfresco instalation files, and separate modules a avaiable also there
You can install Alfresco on Ubuntu distributions for by using Alfresco Ubuntu Install script from Loftux AB.
While you are installing using the script, you can select between Alfresco Community Edition (No commercial support) and LXCommunity ECM (With commercial support).
Additionally you can extend you Alfresco with community created addons- they are avaiable on https://addons.alfresco.com