QLPrettyPatch is a QuickLook generator for patch files.

Once installed, you can select patch file attachments in an email or patch files in Finder, hit spacebar and get a colorized/prettified representation of the patch.

From the Terminal, you can also run qlmanage -p /path/to/my.patch to open the patch in a QuickLook preview pane.

There are two options for installation:

1. To install a pre-built copy, head to the Releases page and download the latest QLPrettyPatch.qlgenerator.zip file. Unzip the archive, and copy QLPrettyPatch.qlgenerator to ~/Library/QuickLook/.
2. To build your own copy, clone the project, open QLPrettyPatch.xcproj in Xcode and build the Install target. The build product will automatically be copied to ~/Library/QuickLook/QLPrettyPatch.qlgeneator.

QLPrettyPatch uses the incredibly useful PrettyPatch formatter, which is used by the patch review system on bugs.webkit.org.

If you find yourself sending emails with patch attachments and want to include a prettified version of the patch in the email body, you should take a look at my atnan/purdypatch command line tool. It uses the same underlying formatter as this QuickLook generator.