You can edit Wiki pages collaboratively (think Google Docs). In the figure shown here, four users are editing the Wiki page simultaneously. Their avatars are displayed next to the title page. Note that each user has one color associated with them.
In the example, the user who has a green color, has highlighted the word “Project”, so that it is also highlighted in green. Another example, is the blue user – her mouse cursor is next to the word "progress".
Hover on an avatar to see user details:
Hover on the highlighted text to see who highlighted it: