To that end, I've tried a number of visual diff-ing tools, ediff, vimdiff, kdiff3, kompare but none beats Meld.
Usability is where Meld trumps the competition:
- Use of curved lines and color highlighting to show different types of changes.
- Works with pretty much every source control system there is.
- Does directory diffs really well.
- Has both 2-way and 3-way compares.
- Has syntax highlighting, line numbers.
- Works from command line.
- ... and more
To see changes you made to your code base:
meld .
To see changes between checkout subversion trunk/ and branch/
meld path_to/trunk path_to/branch
You can also use meld as a parameter to --diff-cmd for your source control client.
With either fink or macports you can get it on Mac.
