The emacs editor includes a third family of Major modes that are not oriented toward a particular language or toward ordinary editing. Instead, these modes perform some special function. The following modes might define their own key bindings and commands to accomplish that function:
• Rmail: reads, archives, and composes email
• Dired: moves around an ls –l display and operates on files
• VIP: simulates a complete vi environment
• VC: allows you to drive version-control systems (including RCS, CVS, and Subversion) from within emacs
• GUD (Grand Unified Debugger): allows you to run and debug C (and other) programs from within emacs
• Tramp: allows you to edit files on any remote system you can reach with ftp or scp
• Shell: ...