Hex pretty much transformed web software (9)
I believe the answer is:
hypertext
'web software' is the definition.
(software used for websites)
'hex pretty much transformed' is the wordplay.
'much transformed' indicates an anagram.
'hex'+'pretty'='hexpretty'
'hexpretty' with letters rearranged gives 'HYPERTEXT'.
(Other definitions for hypertext that I've seen before include "A website technology" , "Software system" .)