Most of the online casinos don't develop their own software. Instead, they buy one of the most popular software made by well-known developer companies. Here are the most popular online casino software:

1. Microgaming - Viper

Microgaming's Viper is one of the most popular online casino software. The company has been on the market for over one and a half decades and is very successful. It was founded in 1994, and has been growing ever since. In 2002 with the software called Viper, they attracted all the attention again.

This Viper software nowadays is the No1. on the online gambling market, and it’s one of the most efficient software that an online company ever developed. It is extremely popular among the operators as well as the players.

Microgaming’s Viper software offers the most online slot machines on the online casino market , thanks to the customisation and diversity that the software design provides for the various casino operators.

Advantages:

•    User-friendly interface
•    Browser based and ‘instant’ gaming software
•    Well established business – since 1994
•    Founding member of eCogra (online gambling regulation and security organisation)

Disadvantages:

•    The full screen mode is usually a default setup
•    The video clips shown before play can be annoying after a while

2. Playtech

Playtech has become one of the biggest producer of the market since it was founded in 2000. They are specialized in creating gaming systems. They are not only present in the casino software industry, they also develop Poker, Bingo and other skill game software. Therefore they offer a wide variety of gambling software but none of them is exceptional.

They offer downloadable and instant play software as well, with multiple languages and currencies.

Their casino software includes over 60 games – each appears in 3d graphics

Advantages:

•    Black jack hands are really fast

Disadvantages:

•    They rarely update with new games

3. RTG

RTG is an American casino software, founded in 1998. RTG stands for Real Time Gaming. Their goal was to create the best online casino software, and many online casino player believes they did. Their software includes a collection of the most famous casino games, wich mainly focuses on versions of blackjack and video poker. The software is really user-friendly and quick – RTG developed today's fastest blackjack software.

Every RTG casino accepts American players.

Advantages:

•    Small sized games upon downloading
•    Best video poker software
•    User friendly Lobby
•    Over 100 games

Disadvantages:

•    The no-download version is not great
•    Graphics and sounds are not very good either

4. Rival

Rival was founded by a Cipriot firm, Black Chip Ltd in 2006, and developing it ever since. Rival is a relatively young casino software, still it is used by some well known online casinos, because of its reliability.

It developed iSlots which are unique slot machines on the online casino market. ISlots’ aim was to create an interactive, genial softwares, of which the players could feel it is their own.

Another attractive thing in the software is that the download time of the games, compared to other casinos is really fast.

All rooms working with the Rival software accept American players.

Advantages:

•    Great audio and visual experience
•    Accepts US residents
•    MAC compatibility
•    Unique iSlot games

Disadvantages:

•    Limited Blackjack and video poker choice

5. VegasTech. 

The Vegas Technology company was founded in 1997. Their online casinos welcomed players worldwide; from The USA, UK, and Australia as well.

Vegas Tech casinos closed down in 2025 after the United States banned American players from playing in online casinos.