Abstract: A system and methods for editing, storing, sharing notes and, arranging and displaying a plurality of notes according to hierarchical trees of notes. A note comprises a content, one or more members and optionally parent notes. A member of a note is a user of the system who have access to the note. A parent note of a note specifies a parent child relationship between two notes within a hierarchical tree of notes. The system and methods described herein allow a user to create a note, to specify which users have access to a note, to revise the content and the members of a note and to delete a note. The system and methods described herein further allow a user to arrange the notes to which he/she has access in a hierarchical tree of notes, said notes being shared with different users.