Everybody who enjoys their online casino will have their favourite casino games and for those that play at more than one of the online casinos may have noticed that the same casino games are available. This is especially noticeable in the area of casino slots as well as the range of other games such as Red Dog or Caribbean Stud. The reason for this is simply that most online casinos do not write their own casino software any more preferring instead to come to some commercial arrangement with one or more of the specialist casino software suppliers that have emerged. There are in fact five major casino software suppliers that control most of the market and a brief description of each can be found on the casinos.ie site and in no particular order are Cryptologic, NetEnt, Microgaming, Playtech and Chartwell. Your choice of online casino will very much depend therefore on the casino software which that online casino uses as this is what determines which games are available as well as the graphics and soundtracks although everybody probably has a feeling of doing better at one online casino than another. The only thing that is not controlled by the casino software is of course any casino bonus that you might receive as a new player. Interestingly enough it is also the casino software that takes care of the huge progressive jackpots that are available on some video slots as on each spin a very small amount is taken to contribute to the jackpot regardless of which online casino you are playing at. In this way the jackpot builds much quicker than it would on a single online casino site and it also goes some way to explain why an online casino is very happy when someone wins a huge jackpot on their site as it is good for business and in principle costs nothing more.