nostr:npub17tdadn0j58jjrekysl4ley0nlzzge58w5nuw7knncr8mk4vacfkqz3apfk LibreOffice.  I like that, while it does resemble Microsoft Office somewhat, it's far far more light and efficient.  Plus, you know, open and free.  It runs great even on an old Raspberry Pi.  (As far as I know OpenOffice is considered depreciated in favor of LibreOffice and shouldn't be used anymore btw.)

BTW Freeoffice isn't quite as free as it makes out to be.