I did a great deal of research on this topic before deciding on a product. Xibo in the end seemed to meet my requirements, which were open source, not limited or in any way evaluation grade, and easy to learn to operate. Xibo met these criteria for me.
Installation was fairly easy. To be honest, I would have preferred to use the software on an Ubuntu Linux server, but time was fairly limited, and I had difficulty getting all of the dependencies and permissions dealt with. To be fair, a large part of that is how infrequently I work with the command line anymore. So I built the server on Windows Seven. Since this was to be a dedicated machine, I also installed the Xibo client on the same computer.
The major requirements are simply a LAMP or XAMPP server and the software itself. Check the Xibo documentation on the site listed below for more details. There is some minor configuration to do in order to make sure that the software can access directories needed to read and write files. There are also clients (where the content is displayed) for Windows and a Python-based client that purports to have additional functionality.
So far we have not placed the display in the hallway, so this is really simply an introduction. I expect to have the actual display installed in the next few weeks. I will post again once I have the completed design for the screen output and the display is mounted and activated. I should have some more detailed observations then.
