This is Digital Distortion Message Reader, which offers a scrollable reader interface for ANSI users (and falls back to a traditional interface for non-ANSI users).  Also supports searching & scanning (i.e., message newscan, new-to-you scan).  Additional features include built-in lightbar message list and message area chooser, as well as configurable colors and text strings.  This is still in beta but is fairly mature and stable.  The first official (non-beta) release will probably happen soon.