Fisheye's 'side-by-side diff' view allows you to see how a file's content has changed. Different versions of the file are displayed together to make line-by-line comparisons easy. 

Show the side-by-side diff view

1. Open the source code view for the file. See Viewing file content.
2. Use the elect a range of revisions to compare.
3. Choose View > Side-by-side Diff.

Note that:

• Green highlighting indicates where lines have been added; red shows where they've been removed.
• Grey highlights indicate that a line's internal content has changed.
• Each addition or deletion is linked to the adjacent pane by a colored triangle to show the location of that change in the comparison file.
•  Line numbers in the margin are permanent links ("permalinks") that can be sent to colleagues. When they open those links, the view will automatically open in side by side diff mode. 

Alternative ways to open side-by-side diffs

From the Fisheye Dashboard

You can also open side by side diffs from the Dashboard screens, by clicking the 'Delta' triangle icon next to an item when it appears in the stream of events. This will open the file in the diff view. If you have currently selected side by side diff as the viewing mode, then the diff will automatically be displayed in that mode. If not, you can select side by side diff from the View menu.

From the Revisions History view

When in the revisions view, you can show a diff by checking the boxes next to two revisions, then clicking the Diff in the top control bar. If you have currently selected side by side diff as the viewing mode, then the diff will automatically be displayed in that mode. If not, you can select side by side diff from the View menu.

You can also launch into a diff of the latest revision and the second most recent by clicking Latest Diff in the top control bar.