Adapter modules, housing assemblies that house the adapter modules, and frame assemblies that contain the housing assemblies are disclosed that are all relatively compact and support a relatively high density of components. The modules, assemblies and frames have configurations that take advantage of bend-insensitive cable fibers and jumper fibers. The adapter module is a cassette-like case that allows for a length of cable fiber to be wound tightly therein in a substantially circular loop configuration when closed. The housing assembly houses a plurality of adapter modules and is configured so that the cable and jumper fibers have relatively tight bends within the housing interior. The frame assembly is configured to support a plurality of stacked housing assemblies and to route the jumper fibers through routing conduits and/or routing troughs so that the jumper fibers are enclosed within the frame assembly rather than dangling outside of the frame. The cable fibers enter the back of the housing assemblies via a fiber optic cable arranged at the back of the frame assembly.