Long time I was searching for an application which does what you can read in the title of this posting.
I was working with Mac OS X panther, so it was even more difficult to find an app, because of an old OS and a G4 Prozessor.

Now with my new Mac I can use and test the recent apps for my needs. In the windows and linux world are the following apps very popular:

For Mac OS X however it’s hard to find such popular and worth proved tools. These days I found a saving blog post from echeng and many useful comments for my problem.

For a better overview I made a list of the mentioned code/folder compare, sync, diff and merge applications:

My decision flew to diffmerge because it’s free and does what I want – albeit not very intuitive but it does – namely show me the differences between folders and the exact differernces in the file contents.

When I have the time I’ll enhance more information. You’re invited to help me ;-)

Thx to echeng and the commentators.