[adolph]

Netcraft indicates Linux or unknown previous to the incident for www and bl.uk:

https://sitereport.netcraft.com/?url=http://www.bl.uk

  Hosting History
    
  Netblock owner IP address OS Web server Last seen
  Microsoft Corporation One Microsoft Way Redmond WA US 98052 13.107.213.64 Linux unknown 26-Nov-2023
  Microsoft Corporation One Microsoft Way Redmond WA US 98052 13.107.246.64 Linux unknown 25-Nov-2023
  British Library 194.66.233.215 Linux unknown 20-Jul-2023
  British Library 194.66.233.215 Linux nginx 15-May-2019
  British Library 194.66.233.215 unknown nginx 5-Jul-2016
  British Library 194.66.233.215 Linux nginx 4-Jul-2016
  British Library 194.66.233.215 unknown nginx 26-Jun-2016
  British Library 194.66.233.215 Linux nginx 21-Jun-2016
  British Library 194.66.233.215 unknown nginx 17-Jun-2016
  British Library 194.66.233.215 Linux Apache 17-Jan-2016

[Moru]

Does not have to be what they are running their servers on.

[adolph]

Very true. This website[0] by a library consultant says the library system was “Aleph 500.” The product documentation[1] says it is an Oracle on RHEL. Other components also indicate Unix flavors.

0. https://librarytechnology.org/library/3413

1. https://knowledge.exlibrisgroup.com/Aleph/Product_Documentat...