ELF

Executable and Linking Format (ELF) is the extension used on Wii mode Wii homebrew files. It is a standard format used for executable files, object files and shared libraries on most modern unix like systems. More information can be found at here.

This format is supported by many Wii homebrew loading techniques, particularly the Homebrew Channel, although most methods also support Nintendo's .dol format, and some methods only support one or the other.