Below, is a run-down of the slot manufacturers who release online slot machines with 1 Minute videos highlighting the main games.
Aristocrat Slot Machines
Aristocrat have awarded two licences to online slot developers: Game Account and NextGen Gaming. Each developer has a list of games they can develop and the slots in the video to the right are those from Game Account. One main difference between the two is that NextGen allow the bulk of their games to be played in free-play with no registration requirement so that's why this site has games like Queen Of The Nile II rather than the original which is one of the Game Account-developed slots. For more detail on all the games, check out the Aristocrat slots page which goes into much more detail.
Novomatic Slot Machines
Unlike Aristocrat, Novomatic slots (sometimes branded as Admiral, Gaminator, Novoline or Novostar) are developed by one of their own subsiduary companies, Greentube. The licences for Novomatic slots can be quite expensive I'm told which would explian why there aren't that many online casinos that have their games. Some of their 'premium' slots like the very popular Book Of Ra and Dolphin's Pearl along with Lucky Lady's Charm (the Deluxe versions) are a little more common and available as free-play games, hence why I have the first two here. Their "fruits" series is also online; Xtra Hot, Power Stars and Sizzling Hot among them.
IGT Slot Machines
IGT were the first land-based slot developer to start releasing their games online. They bought Wagerworks and Barcrest (before selling the latter and folding the former!) and launched with games like Cluedo, Monopoly and the very popular Cleopatra before adding a wealth of titles. They run their own online casino Kerching which has all their slot machines plus they licence out to a number of other casinos and games sites. For some odd reason that I've never worked out, their most popular game Pharaoh's Fortune is really hard to find online and not even Kerching has it!
Williams Slot Machines (WMS)
Williams draged their heels a bit bringing their games online but now they are here with a pretty large selection and I'm a big fan. They produce their games through theirown Williams Interactive subsiduary and licence them to a small but growing number of very good online casinos like Unibet and Bet365, releasing one or two new slots every month. On this site you will find two of my favorites: Zeus III and the Double Money Burst Elvis The King Lives. I expect you'll see more added soon too!