All the data displayed on the map is from the Openstreemap open database. This is why some data may be missing or incomplete. If you want to help us improve this database, please check OSM wiki. Any help is welcome !
If you have any comment or suggestion about the website and/or the map in itself, you are free to leave a comment on the GitHub reposery.
If you are interested, there is a specific version of this map for Paris and its region, including realtime itineraries and links to timetables.