Develop layer to encapsulate software (6)
I believe the answer is:
happen
'develop' is the definition.
(thesaurus)
'layer to encapsulate software' is the wordplay.
'layer' becomes 'hen' (I've seen this before).
'to encapsulate' means one lot of letters goes inside another.
'software' becomes 'app' (I've seen this before).
'hen' enclosing 'app' is 'HAPPEN'.
(Other definitions for happen that I've seen before include "maybe, in the Yorkshire Dales" , "Take place" , "Chance" , "Come to pass" , "Turn out" .)