What tools exist to display patch files? A text editor is usually good enough. ColorDiff can add color. Ideally though the tool would also show intra-line differences like KDiff3.
3 Answers
Try the plain text mode of Pretty Diff:
If your using Gnome, Meld is what I use for viewing Differences / creating patches. Haven't had a problem with it so far.
If you're on Mac OS X, PatchViewer lets you use existing GUI diff tools to view patch files: http://appledeveloper.com.au/patchviewer.html
(Disclaimer: I am the author of PatchViewer.)