A network-accessible toolbox permits collaborative annotation, facilitating interaction and communication among users. In an implementation, content on a Web page, or other page or document accessible through a network or the Internet, can be annotated. A user can view the page and with the toolbox, select content on the page and make an annotation or suggestion. Multiple users can view and make annotations to the same page at the same time. After annotations are made, users can view the page with annotations made by other users. The author or owner of the page can accept or reject the annotations or suggestions made to the page. If the owner accepts a particular suggestion, the selected content is replaced with the suggestion.