They would fall under the "All Other Cruise Lines". River cruises is a Niche cruise and not as many people have done them as they have the major cruise lines. I did a wonderful Christmas Market river cruise on the Danube last December from Vienna to Nuremburg. I did it on Avalon Waterways and loved it. There are mainly four river cruise suppliers. Avalon, AMA Waterways (formerly called Amadeus), Uniworld, and Viking. They can be very similar in price, but the thing to look at are the inclusions, age of ships, and square footage of cabins. AMA and Avalon ships have the newest ships in their fleet. Avalon's cabins have larger square footage on an average at 172sq ft. Avalon, AMA, and Uniworld include wine, beer, and soft drinks with dinner, Viking doesn't, although they have been offering some specially priced packages where wine is included. Viking has been having some attractive 2 for 1 pricing but you have to really look at the small print and bottom line. I think all four have some type of shore excursions included . A lot of these are walking tours. I loved my Christmas Market cruise and can't wait to do another river cruise. I've also done a river cruise on the Yangtze. I'd like to try the Rhine next or the Mekong.