Example systems and methods of displaying semantic layers of source code of a computer program are presented. In one example, a user selection of a first portion of the source code is received. The first portion is displayed in a first display area and corresponds to a first semantic layer of the source code. A user command referring to a second portion of the source code related to the first portion is received, with the second portion corresponding to a second semantic layer of the source code. In response to the user command, a second display area for the second portion of the source code is displayed to indicate a relationship between the first and second portions while indicating a difference in semantic layers between the first and second portions.