- Tabbed interface with multiple panes
- Every function can be assigned a shortcut
- Every button can be scripted
- Defaults can be overwritten
- Dynamic layouts based on folder contents, path or determined by a script
- Custom file previews, context menus, rename scripts
- Hooks for reacting to different events
- Every corner of the UI is themable
- Virtual filesystem for archiving and bookkeeping
- ...
One disadvantage is that you have to use an ancient version of JScript (ES3 / Microsoft flavor) or VBScript (possibly because of the need for communicating over a COM interface). Or use its own DSL for simpler scripts.
I wish it had support for a more modern / more popular languages for scripting. I wonder if QuickJS[1] can be integrated into it. Or Python. That would be really sweet.