A system, method, and computer-readable media for dividing the content of a user interface for a group-based communication system among a plurality of windows. A parent window may comprise a plurality of panes. A child window may be created from the parent window by an actuation on a pane of the plurality of panes presented by the user interface. Child windows and the parent window may share computer memory. A plurality of windows may be created to divide the content of the user interface. Libraries designed for single window applications may be modified to work with a plurality of windows. The group-based communication system may be implemented via various web technologies.