Setting up WinMerge for addon comparison

Software needed

1. WinMerge - Tested version 2.6.14 installer version
2. Merge7z Plugin - Tested build 0026-432-457 installer verion
3. 7-zip - Tested version 4.57 MSI Installer. While WinMerge is 32bit, you need the 32bit version

Configuration

1. Install all components (I did in the order 7-zip, WinMerge then Merge7z)
2. Launch WinMerge
3. In WinMerge select plugins -> Automatic Unpacking
4. In WinMerge select edit -> options -> archive support -> check 'detect archive type from file signature' to ensure .xpi and .jar files are opened properly
5. Now you can open two files using WinMerge. If you have trouble, let me know.

Let me know if you have trouble setting it up