For Reader, read User; for Writer, Developer, and… you can work out the rest:

John Steinbeck – A Book is like a Man

[…]

WRITER
(Losing temper as a refuge from despair)
God damn it. This is my book. I’ll make the children talk any way I want. My book is about good and evil. Maybe the theme got into the execution. Do you want to publish it or not?

EDITORS
Let’s see if we can’t fix it up. It won’t be much work. You want it to be good, don’t you? For instance the ending. The reader won’t understand it.

WRITER
Do you?

EDITOR
Yes, but the reader won’t.

PROOFREADER
My god, how you do dangle a participle. Turn to page so-and-so.

There you are, Pat. You came in with a box of glory and there you stand with an armful of damp garbage. And from this meeting a new character has emerged. He is called the Reader.

THE READER
He is so stupid you can’t trust him with an idea.
He is so clever he will catch you in the least error.
He will not buy short books.
He will not buy long books.
He is part moron, part genius and part ogre.
There is some doubt as to whether he can read.