Windows Client
Ghidra #
You can plug any Win32 executable into Ghidra and it will happily decompile it. Of course, there won’t be any debug symbols so can be hard to find anything.
If you follow the FFXIVClientStructs Ghidra guide it will give you very helpful tools for getting around. It includes reverse engineered symbols as well as a signature maker, which can help writing hooks for plugins.