To make it worth to be developed in-house, it should includes dedicated features not available outside. I would like to see the idea re-scoped in order to take into consideration what happens before, during and after a meeting. For example with a badge holder-reader. If a room is free ones can enter and put their badge in a special slot on their place. It will then understand the room is not free anymore. It can as well be used to build an attendance list sent to the meeting owner's badge for example. You can the same way than we use the printers with pullprint use a dedicated touchscreen stands where you can have a look at the list of the meeting rooms, perform a search for the meeting room a specific meeting you have to attend takes place (identification by badge to highlight it), book a room now or later in the day for example, and so on. If all the attendees leave the room more than let's say 15 minutes the room turn free even it was booked for an hour more (could be override by some settings like 'keep the room' in the reservation) or if nobody entered the room 15 minutes after the start of the meeting then the room if freed up and all those logics that could REALLY make everybody's life simpler !