While Suze is typing this Latex code, Angel sees that Suze forgets a backslash (\\), so she adds that backslash. Suze works straigh on, but she sees the backslash added by Angel instantaneously. It is marked with the user color of Angel, so it draws her attention. She knows that she probably made an error, so now she chats with Angel, asking why she has to add a backslash when typing C#.
Suze and Angel are working on a highly confidential technical paper. Trusting the drafts to “the cloud” or a third party system was out of the question. They installed this software for collaborative editing on their own Linux server, although they also could have installed it on their own Windows XP client computers. But the server setup allows them to automatically produce a PDF version of their report each five minutes.