A device for capturing commentary, rationale, and other explanatory information pertaining to a document in parallel with the authoring of the document itself. The document content is entered through a primary input device (100), typically but not restricted to keyboard and mouse, and the commentary is entered through a secondary input device (200) of a different medium, such as speech captured by a microphone. The comments are linked to the corresponding locations in the main document by a memory controller (300), which stores the linked structure in the computer memory (400) and sends it to an output device (500), typically but not restricted to a computer monitor display, for presentation of the annotated document to the operator.