That's a screenshot from DiffMerge http://www.sourcegear.com/diffmerge/ http://www.sourcegear.com/diffmerge/ , but I typically just use Git or OS X's built-in "

That's a screenshot from DiffMerge http://www.sourcegear.com/diffmerge/ http://www.sourcegear.com/diffmerge/ , but I typically just use Git or OS X's built-in "FileMerge" program. I was going to use GitHub's diff via a gist, but turns out GitHub Gists don't support diffs.