A collaborative authoring application provides an authoring environment in which two or more users can edit a document concurrently. Each user edits a copy of the document, sends updates to a master copy of the document, and receives updates from the master copy of the document. The authoring environment may be configured into a public mode of operation, in which content and metadata are synchronized automatically, or into a private mode of operation, in which metadata is synchronized automatically and content is synchronized only at the request of the user. The authoring application may edit documents offline in public or private mode.