Author of The HumaneInterface (ISBN 0-201-37937-6 (alternate, search)), a book calling into question many conventions used in computer interfaces.
He argued for a much more keyboard-centric UI, incremental searches, abolition of file names (users should use search to find the right file - but what about binaries?), abolition of the distinctions between different apps, an end to menus as we know them (to be replaced by handy text files with all the commands typed in already), and even much less customizability on the part of the user.
Jef Raskin passed away on February 27, 2005. [1]