US Patent 7284235 Creation of content versions using content layers

The technologies allow a digital content developer to define, and a user to switch between or select, various versions of digital content for purposes of displaying, rendering, improving, or testing digital content. For example, a source code developer inserts identifiers in source code, and a source code layer viewer displays code segment choices defined by the identifiers. A user (e.g., the developer or others) selects code segments for inclusion in a source code version. The technology is also useful for providing versions of media content such as audio, video, DVD, images, text, etc.