I'm looking for a diff/compare tool that shows differing lines from two text files, and gives me a space to comment on those files. Ideally this application would have three panes, pane one would be file A, pane two would file B and pane three would be a comment I can enter to on why the files are different.
We're going to be using this diff tool to compare test and production environments. Sometimes it'll be justifiable that the two files are different but we need to have a space to explain why. I'd rather not write those comments in the files themselves.
I've used TortosieMerge, WinDiff and Beyond Compare. I like beyond compare the most because it lets me see the whole file, just the differing lines or the differing lines in context.
Tools that sit inside Visual Studio or eclipse are fine too.