# Comparing two builds

To compare two crosscutting map files:

1. Select two files with the ".ajmap" extension in the Package Explorer.
2. Right click and select AspectJ Tools > Compare Crosscutting With Each Other.

The results of the comparison are then shown in the Crosscutting Comparison view, which is opened in the current perspective if it was not already showing.

The older crosscutting map file is compared with the newer one, and the results are displayed in a table. The first column indicates whether a given crosscutting relationship has been added or removed, i.e. whether it exists in the newer map but not the older one, or vice versa. The remaining three columns show the source element, name of the relationship, and target element respectively. The cells of the table can be navigated with the keyboard or mouse. Selecting a table cell containing a source or target element causes that element to be opened in the editor (except where that element is one which no longer exists).

Saving crosscutting information
Comparing with the current build