A few notes on diff

The differences between versions of the framework code are presented as "context diffs." These files show you the changes that were made between two sets of source files in a nicely readable format: for every change, the affected lines are shown along with a few lines before and after, and the changed lines are marked with '+', '-', or '!' to indicated added, deleted, or modified lines. For additions only the new version is shown; for deletions only the old version is shown, and for changes both are shown.

For every source code file that has any changes, there is a little header that shows you the names of the old and new files and indicates that the old file is denoted by asterisks and the new one by hyphens. Then for each change the line numbers in the old and new files are shown just before the corresponding text.