1. A computer-implemented method for processing tagged input data, comprising: receiving, using one or more processors, tagged input data that is in a non-rectangular format and that uses a hierarchical arrangement of tags to indicate data relationships; displaying the tagged input data in a graphical interface; and using the graphical interface to create a mapping specification from the tagged input data, wherein one or more tagged data items are displayed in a first region of the graphical interface, wherein a changeable view of the one or more tagged data items is displayed in a second region of the graphical interface, wherein an interactive view of the one or more data items is displayed in a third region of the graphical interface, wherein an interface view of the mapping specification generated by input into the interactive view is displayed in a fourth region of the graphical interface, and wherein a create view of code generated based upon the mapping specification is displayed in a fifth region of the graphical interface.