The person who writes on behalf of some one else is called a biographer.
A Philosopher
A secretary
A journalist.
I believe it is "Reporter". Hope that helps:)
biblioraptor
An author is a person who writes and sells books.
an auto-author, or the author of an autobiography.
The person who makes a will (or 'testament') is a testator.
A Philosopher
A person who writes the libretto for an opera is simply referred to as the librettist.
an author!!
A drawer.
proposal
publisher
A poetry
A person who writes verses is a poet.
A columnist...?