This compiler brought up aim to improve (5)
I believe the answer is:
emend
'to improve' is the definition.
(emending is a kind of improving)
'this compiler brought up aim' is the wordplay.
'this compiler' becomes 'me' (the person who is writing these clues).
'brought up' says the letters should be written in reverse (in a down clue, letters go up).
'aim' becomes 'end' (both can mean a goal or purpose).
'me' back-to-front is 'em'.
'em'+'end'='EMEND'
(Other definitions for emend that I've seen before include "Improve by altering" , "Alter to improve (text)" , "Edit; make alterations to a draft" , "get rid of faults" , "Make changes to (a text)" .)