Computer programs tanks to surround castle (8)

I believe the answer is:

browsers

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'computer programs' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'tanks to surround castle' is the wordplay.
'tanks' becomes 'bowsers' (bowser is a type of tanker).
'to surround' is an insertion indicator.
'castle' becomes 'r' (abbreviation for rook/castle in chess).
'bowsers' placed around 'r' is 'BROWSERS'.

Can you help me to learn more?

I've seen this clue in The Independent.

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