Show all major and minor modes available in Emacs.

M-x mode-minder

• Nested major mode heirarchy, useful for targeting mode-hooks, etc.
• Standalone major modes
• Minor modes
• One-line mode description
• A clickable help link for the mode
• An origin tag:
  • [P] for modes found in packages installed by the default package manager
  • [O] for other non-builtin packages
• Aliases to the mode in parentheses, if any

Note: on first invocation, all known major-mode libraries are loaded with require.