Yet another directory compare/merge tool, inspired by commercial tools like Beyond Compare.
https://github.com/fourier/ztree#ztree-diff
Functionality
Implemented recursive directory comparison while comparing on per-file basis. The per-file comparison performed with external GNU diff tool. Supported features:
- Two trees in one buffer
- Colors differentiation for absent, different or identical files
- Hotkeys/Operations:
- Run Ediff on different files with the RET, or run simple diff with d or Space key
- Copy files or directories with the C key
- Delete files or directories with the D key
- Hide/Show identical files with the H key
- Refresh of the current file/subdirectory with r, force the full rescan with the F5 key
- Fast jump between panels with TAB
- Backspace - jump to upper directory, double backspace - close current directory
- Space/RET to expand/collapse directory, or
- Quick view the current file with v key
- Toggle between expanded/collapsed state of the directory under the cursor with x key
Screenshot: 
Screenshot with diff command called (d hotkey): 