Use SmartSynchronize with CodaSmartSynchronize is a source comparison tool / Coda is an IDE
SmartSynchronize, from Syntevo, is one of the best source compare utilities, imo. Coda is by far one the best IDEs, made by Panic and it uses the 'opendiff' Unix-command to start a source-compare session of different versions from an SVN-repository.
Opendiff normally starts Apple's FileMerge but we want to use SmartSynchronize! So, the first step is to find out how we can use SmartSynchronize from the command line. A little research reveals that you can use this command:
/Applications/SmartSynchronize/SmartSynchronize.app/smartsynchronize.sh file1 file2
The next step is to replace opendiff.
If you already assigned opendiff to another source-compare utility, like Kaleidoscope, simply delete it:
sudo rm /usr/bin/opendiff
Otherwise, save the original by renaming it to something like this:
sudo mv /usr/bin/opendiff /usr/bin/opendiff.apple
Next, create a new opendiff by creating a link to smartsynchronize.sh and call it opendiff:
sudo ln -s /Applications/SmartSynchronize/SmartSynchronize.app/smartsynchronize.sh /usr/bin/opendiff
Now, start Coda, right-click a source file, choose Source Control->Compare with->Revision...
Pick a revision and now SmartSynchronize will be used to compare both source files.
If you previously used Changes for source comparison, open Terminal and execute the following command to remove the Changes-plug-in from Coda:
rm -rf ~/Library/Application\ Support/Coda/Plug-ins/ChCoda.codaplugin