Compiler had been at the forefront and did nothing (5)
I believe the answer is:
idled
'did nothing' is the definition.
(I've seen this before)
'compiler had been' is the wordplay.
'compiler' becomes 'I' (the person who is writing these clues).
'had' becomes 'd' (I've seen this in other clues).
'been' becomes 'led' (leading is a kind of being).
'i'+'d'+'led'='IDLED'
'at the forefront and' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for idled that I've seen before include "Of engine, just ticked over" , "not worked" , "was unoccupied" , "Was lazy" , "Lazed around" .)