1. A method for enabling concurrent editing of a document containing a plurality of independent or loosely connected segments by multiple authors, comprising the steps of: assigning editing rights for each segment of a document to a defined set of segment authors, wherein the editing rights enable each segment's set of authors to create or change their respective segment of the document, and wherein the creating or changing includes concurrently creating or changing the respective segments; making available a special segment of the document, wherein the special segment contains metadata of the document shared by all the segments of said document; providing email means private to said document, for enabling such an author of the document to send a email message to a certain one of the segments of the document, the email message being addressed to an author of the certain segment; and displaying the email message responsive to such an author of the certain segment of the document browsing or editing the certain segment.