Very common English idiom that appears to stem from World War II - in heavy bombardments, the enemy was said to be firing everything but the kitchen sink. It means something like '*almost* absolutely everything you can think of'.
Perhaps surprisingly, EMACS indeed does not include any 'kitchen-sink, so it can count as a canonical example.
Nethack, however, does. It is one of the few things that include everything including the kitchen sink.
Of course, Everything is another.
Everything includes the kitchen sink as well as everything but the kitchen sink, by definition.