Early IT system with tip for butterfly hunters (6)
I believe the answer is:
usenet
'tip for butterfly hunters' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'early it system' is the wordplay.
'early' becomes 'us' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'system' becomes 'net' (net is a kind of system).
'us'+'e'+'net'='USENET'
'with' is the link.
Can you help me to learn more?
(Other definitions for usenet that I've seen before include "news system" , "Newsgroups worldwide" , "Internet facility" .)