Slot machine companies that long dominated the bricks-and-mortar casino industry now design online slots. Land-based slot machines are computers built inside game boxes that advertise the game’s features and display jackpot amounts. They are like slot machine video games, but with ATM-style cash dispensers. Each machine takes up space on slots row, but electronics make it more efficient than it was in the 20th century.

The traditional slot software companies have rivals in the online casino industry. In the early to mid-1990s, a small group of casino game designers launched that became highly successful. Microgaming, Playtech and RTG were only a few of the successful startups. Those companies now compete with the land-based slot developers: IGT, Bally and WMS, to name a few.

Thanks to the competition, players have more and better real money slots to play than ever before.

Most Popular Slot Game Developers

Below is an organized list outlining the most popular slot machine companies available for both online slots and B & M slot machines. Each review covers some of the more prominent features, most popular games and casinos offering their product.

Online betting today is a multi-billion-dollar-a-year industry, and the number of game designers offering suites of software for internet casinos has swelled considerably. Below are short reviews of the most popular slot game designers in the business and a few details briefly outlining what each designer offers. Depending on what style of slot game a gambler prefers (what wager sizes are available, the presence of progressive jackpots, 3D graphics, customizable in-game options, etc.), a suite of casino software addressing those needs likely exists.

The number of slot and other casino software design companies has increased greatly since the first website to offer real money wagering launched in 1996. The 18 design groups below represent the best-known names in the business.


RTG Slot Software

RealTime Gaming (known as RTG in the industry) is one of the oldest designers still in the business, formed in 1999 soon after the first casino sites started taking real money wagers. RTG offers games in both instant-play format and a download that’s designed to be as small as possible while still providing high-quality graphics, sound effects and plenty of features that appeal to slot machine fans. Bonus games, progressive jackpots and a range of different game themes has made RTG one of the most popular designers for bettors looking for one-armed bandit action.


Aristocrat Slots

Aristocrat is the famous Australian pokies manufacturer. Originally an Aussie-only company, Aristocrat now has slot machines throughout the world. You’ll also find the group’s slots in top online casinos. Games like 50 Lions, Buffalo Slots, Cleopatra II, 5 Dragons, and Choy Sun Doa are among the most popular slots in the world. They’re now available as online slots (or online pokies).


IGT Slots


International Gaming Technology, or IGT for short, is another of the big boys in slot and casino game design. IGT is an American company that designs games for land-based casinos and online betting venues. Some of the most popular online slot games are built around licensed themes, incorporating actual audio and video clips as well as characters and symbols from movies, TV shows, board games and comic books. Slots based on pop culture icons like Wheel of Fortune, Clue and Monopoly are a big part of IGT’s appeal to bettors hunting for internet-based slots.

Bally Technologies Slots

Bally Technologies began as Bally Manufacturing in Chicago in 1932 – as a pinball machine manufacturer. By the late 1930s, the company was building mechanical slot machines. In the 1960s, Bally controlled over 90% of the global market in slot machines. By the 1980s, the company owned casinos in Atlantic City. In 1993, the slot machine division became Bally Gaming International, including its lottery division (Scientific Games). In the electronic slots age, Bally remains a top gaming machine designer in online and offline casinos. Today, Scientific Games owns Bally Technologies.


WMS Gaming Slots

WMS Gaming or Williams Interactive is one of the oldest game designers in the world. WMS began as a pinball manufacturer known as Williams Manufacturing in 1943 in Chicago. Midway Games began designing arcade games in 1973, then purchased WMS Gaming in 1988. By 1996, WMS was famous for games like Mortal Kombat and NBA Jam. By that time, WMS was making electronic slots machines (1994). Today, it is one of the largest slots manufacturers in the world. Like Bally, it is part of Scientific Games’ huge list of slot designers.


Playtech Slots

Playtech is similar to RealTime Gaming in terms of the length of time they’ve been creating slot games and other gambling software. In the online casino business, the number of years a designer has been in business is directly related to the variety of games in their arsenal. Operating since 2000, Playtech is known for designing slots in a variety of formats that match the varied interests of machine gamblers, though they don’t release a huge number of new titles with the frequency of some of their competitors.

Rival Gaming Slots

Rival Gaming launched in 2005 as a US-friendly online casino software provider. In the past 15 years, Rival produced over 200 casino games, including online slots, table games and video poker titles. In that time, the company became one of RTG’s main rivals in the US gaming industry. Rival’s progressive jackpots are not as big as RTG’s, though their online slots are popular. Rival’s better known for its many slots features like wild symbols, scatters, multipliers and free spins. Its i-Slots Series (interactive slots) have been big hits with the American audience.


More Top Slot Designers

While our slot reviews focus on the companies above at the moment, many great slot designers exist. Below is an overview of the other top competitors in the world. In time, we plan slot reviews for each of the great design houses below.


Microgaming has the distinction of being the provider of the first gambling software used to accept real cash wagers over the internet. Slots with progressive jackpots are popular to a certain set of slot machine fans, and Microgaming’s website claims that the company’s large roster of progressive slots have paid out more than $225 million in cash on their progressive games alone.

NuWorks Slot Software

NuWorks is a relatively young designer of online slots and table games, but the company has managed to carve out a niche for itself by producing beautiful and heavily themed slots. The majority of NuWorks’ games incorporate video bonus rounds and their titles allow for many different wage sizes and coin denominations, meaning their games match the budget of just about every online slot machine player – including players who prefer the penny slots.

Betsoft Games

Betsoft is popular with online slot players because all of their machines include wild symbols, multipliers, scatter symbols and bonus rounds, just the sort of features that internet slot fans are hunting for. Though Betsoft has a limited number of licensed games, the company adds enough extras into their slots to keep gaming fans entertained.

Betsoft’s claim to fame is its graphics. It takes pride in a big library of feature-rich games filled with 3D animation. A controversy involving a slots jackpot caused Bovada to drop Betsoft Games a couple of years ago, so players should keep that in mind when playing their games.

WagerWorks Slot Software

Though IGT acquired WagerWorks some years ago, the company continues to produce new titles as a kind of in-house design studio. WagerWorks gives IGT even more branded games for their casino clients, and plenty of slot players online are drawn to these licensed titles simply because of brand recognition.

WagerWorks’ best-known creations are slots built around classic board games, for example the Monopoly series of slots that WagerWorks updates with new features and new rules many times each year.

Top Game Technology

Top Game boasts one of the fastest downloads in the business, meaning customers at Top Game-powered sites can access the higher-quality download versions of slots and other casino games without taking up too much of their computer’s memory. Top Game Technology’s games are available to a big chunk of the world population, because they are designed for multiple currencies and multiple languages. Because Top Game has only been in business for 10 years or so, they don’t have the variety of titles found on other platforms, but their variety is growing as their list of member casinos increases.

SPIELO G2 Slot Software

A Swedish designer formerly known as Boss Media, SPIELO G2 is a popular designer thanks in no small part to their unique themes that pay attention to details and use side games and bonus rounds designed to make slot machine play more like video gaming than traditional gambling.

Offering games in a half-dozen different categories, like penny slots, multi-payline games and traditional-style titles means internet casinos running SPIELO G2 offer their customers not just title variety but a ton of choices in terms of how much they want to wager. An example of SPIELO G2’s obsession with releasing games that appeal to a large audience is their World Cup-themed slot featuring a skill-based bonus round and other elements close to the hearts of soccer fans.

CTXM Slot Software

CTXM is one of many casino game designers that also offers management and back-end services to their clients, not just slot games themselves. CTXM has offices all over the world and is at the front edge of a trend toward social media gambling and interaction between players, making online gambling a little more like traditional casino action.

CTXM slots are available for play across a lot of different operating systems and platforms; slot gamblers who may not otherwise have access to their favorite way to gamble because of restrictions on compatibility with Macs, PCs, tablets, smartphones and other gadgets can always find a CTXM-powered site that meets their hardware and software needs.

NetEnt Slot Software

Net Entertainment, known as NetEnt, has designed some of the most popular slots in the industry, including a series of titles based on the ultra-popular TV cartoon South Park. NetEnt is releasing more and more mobile platform slots along with their already-large collection of browser-based slots; machine gamblers who don’t always want to play on their home computer can turn to NetEnt-powered gambling venues on iTV, iPhone, BlackBerry, Android devices, and (coming soon) a collection of Facebook slot titles that may one day allow real money wagering via social media.

GTS Slot Software

Gaming Technology Solutions, or GTS, is another company that goes out of its way to produce unique slot titles to capture the imagination of gamblers used to the same old themes and sets of rules they have to play over and over again. The best example of GTS slot machines’ unique style is their game Slot Box, which is a hybrid of the classic video game Tetris and traditional slot play.

Instead of betting on reels and paylines, Slot Box players have to use their hand-eye coordination and other video game skills to form winning symbol combinations. This sort of hybrid game design is not unique to GTS, but they have been building unique titles as long as they’ve been in business, and since online slot machine fans are always looking for something new in game designs, GTS is a good choice for players tired of playing the same titles and styles of games repeatedly.

Chartwell Slot Software

A recent acquisition of Chartwell by Amaya Gaming expands both groups’ list of game titles and gives sites running their software even more variety in all aspects of slot play. Chartwell is another design company that also does business with online casinos looking for management products and not just the software for games – but slot gamblers aren’t interested in casino management so much as they are with game design and play features.

Chartwell has both needs covered, currently boasting some six dozen titles with rich and detailed graphics, themes that lead to entertaining gambling experiences with loads of replay value, and an ever-increasing roster of venues that host their titles giving players the choice of where they do their cash gambling. Slot Software

When bwin and Party Gaming merged in 2011, the result was a company with a massive roster of casino games (some 400+ as of this writing) and a company prepared to deal with big changes in gambling legislation worldwide. has also just released the first Facebook slot machine games tied to real money gambling sites, though as of the time of this review, real-cash bets on the slot games has produced on Facebook are not available.

In the next few years,’s $50-million investment in the development of social media slot machine play could pay off big for the group, which merged in part to increase the variety in slot and other casino games as well as to deal with more customers from different parts of the world where online gambling is just starting to pick up speed.