Nope! Celebrity is owned by Royal Caribbean cruise line. They brought Celebrity cruises in in 1997 for $1.3 billion. Norwegian Cruise Line is owned by Star Cruises which is the World's third largest...
Gill cruises is not a newer cruise line. They have been in operation for about fifty years. In those fifty years, they have been offering very good quality cruises.
It will be a close draw between Royal Caribbean International and Carnival Cruise line. Both are the big players in the Cruising industry as both have 22 ships (if you include Allure of the Seas)....