Bally is mostly known for their extensive live casino operations, which date back to the late 1970s. However, they have started to offer online games as well in recent years.

Formerly known as International Game Technology, IGT is almost certainly the biggest name in casino manufacturing and has created some of the most iconic slot machine names in the world for both live and Internet casinos.

Also known as Williams, you can find this online casino software company’s games at sites around the world – particularly in the United States – as well as at many regulated gambling sites.

High 5 Games are another huge Vegas firm who often release games in conjunction with IGT and Bally. Their games are most popular at land-based casinos in the US, though they are also a hit at social casinos too.

Ainsworth is an Australian developer known for their brick-and-mortar games, as well as their online social slots.

Perhaps the largest and most important of the Australian development companies, Aristocrat has published numerous games for markets around the world, both online and live.

Founded in 1968, Barcrest was once the only name in live machine play, and now offer a handful of their games over the web as well. They provide many games for fixed odds betting terminals at bookies and are part of the Scientific Games Group which also includes Bally and Shufflemaster.

Euro Games Technology (also known as EGT) is based in Bulgaria, but supplies games to casino around the world, and also offers online gaming products through its interactive wing. The names of their slot machines are becoming known around the globe.

This Japanese company is known for many things in the gaming world: everything from gaming machines to console video games. They are still primarily a land-based firm when it comes to producing slots, though they have made some limited forays into the online world.

Formed in 1980, this Austrian company has been particularly successful in Europe and Asia, and has now moved many of their games to the best slot sites online.

One of the largest Internet slot developers since 1999, Playtech is now also a player in the land-based gambling world, making them a major player in the overall gaming industry. Their slots are also available in Ugandan online casinos.

Based in the UK, Ash Gaming offers a small number of games that are particularly popular in their home market.

This online casino software company was founded in 1999, but has only became a major player over the past decade, following the release of their now famous 3D slots.

Since 1996, Cryptologic has been developing software for virtual casinos, making it one of the true founders of the Internet gaming industry.

Primarily known for their social games, Gamesys has also made a number of slots that can be played for real money, particularly in Europe.

A smaller casino software developer based in Argentina, Leander’s game collection is small but highly regarded throughout the industry.

Once the single most dominant name in online gaming, Microgaming is still one of the industry leaders, offering several hundred top slots to their clients and producing new titles every month.

This Swedish firm has created a mix of original and licensed titles that have proven extremely popular, including some of the biggest progressive jackpot machines in the world. Starburst, one of the provider’s most iconic games, is often featured in no deposit casino bonuses.

This online casino software developer is based in Australia and has been successful not only in creating their own games, but also in porting other companies’ titles to the Internet market.

Mostly known for their mobile casino games development, Play’n GO games have been showing up more and more at new slots sites in recent years.

Rival Gaming is one of the smaller companies on this list, but while they only offer a small number of titles, their games tend to be fairly innovative and popular on the sites at which they can be found.

Also known as RTG, this firm has been in the gambling business since 1998, and have licensed their software and games to countless Internet casino sites. They are best known for their Real Series games, which have retained their popularity for many years now.

While they are very new (only being formed in 2013), Yggdrasil has distinguished itself by creating games with a distinctive style and beautiful animations that truly stand out from the crowd.