A method, apparatus, system, and signal-bearing medium that, in an embodiment, create an amalgamated file based on differences between versions of files. When an edit command directed to the amalgamated file is received, the file to which the edit command applies is determined and a change tag is added to the amalgamated file. The change tag includes at least an identification of the file to which the edit applies. In various embodiments, the file to which the edit command applies is determined based on a specification in the edit command or based on the location in the amalgamated file to which the edit command is directed. Data in the amalgamated file is saved by finding the change tags in the amalgamated file, and saving the associated data to the files identified in the change tags. The amalgamated file may be displayed in a number of different views, where the views display respective subsets of the differences based on the files to which they apply. In an embodiment, one of the views displays all of the differences between the files. In another embodiment, another of the views displays the differences between only some of the files.