Cacoo is a web application that allows you to create and collaborate on diagrams. It offers some powerful drawing tools to use for drawing all kinds of diagrams including site maps, wire frames, flowcharts, network charts and many more. The great thing about Cacoo is that it supports real-time collaboration allowing you to work on the same diagram with various collaborators simultaneously. Multiple collaborators can edit a diagram in real-time. There is also a chat functionality integrated into Cacoo editor that enables users to get direct feedback from their team.