Sorry, I misunderstood your earlier response.
Some activity or building directory type applications are interactive. For example, the display normally shows a 'marketing' slide show or video but when someone touches anywhere on the screen you get a list of the day's activities. When they touch on one of the activities it then brings up a more detailed description, the room the event is in and directions to that location. After a time it goes back to the slide show. For some reason that is what I was envisioning you were wanting and PowerPoint won't do that by itself.
For just a slide show that can be easily edited, PowerPoint probably is the most common way. There are numerous message generator programs out there as well that have preset templates. If they want to be able to change the information easily but not necessarily have to have interaction from the display itself, then a standard display and a PC driving it, either at the display or nearby (reception desk, etc.) is usually more cost effective.