Many aspects of the hosted conference's layout and style can be controlled. OCS ships with a number of themes which can be switched here via drop-down menu. (A variety of themes are also available for download at Theme Gallary.) For even more control, a unique stylesheet can be uploaded as well.

OCS also supports a 'block' system for displaying sidebars. The interface can be customized by moving blocks of information from left to right, and up or down in order for both the left and right sidebars. Moving a block to the middle "unselected" field will remove it from the interface altogether.