You can easily share an file - even with people who don’t have an Alfresco Share account. Clicking the Share action generates a URL that you can send by email or publish using social networking websites.
People with access to the URL can view the file. Those with an Share account have the option of signing in; those without an account can create one.
This option is available in the Document Library Detailed view and on the file preview screen. In the Document Library graphical views click the information icon to see the option.