Houdini 4 Aquarium & Houdini 4 PRO Aquarium
Houdini 4 Aquarium 2014 is a new powerful analysis, database and chess publishing tool, powered by the world's strongest chess engine Houdini 4 and 7-piece Lomonosov Tablebases.

Houdini 4 Aquarium — $65.95 / €57.5
Houdini 4 PRO Aquarium supports up to 32 cores and 32 GB of hash — $94.95 / €86.3

Latest broadcast:
Online Grand Prix 2012
Round 1
Weekly Deals by ChessOK!

From October 31 to November 6, the following special offers are available on ChessOK.com. All offers stack!

Special Offer 1: Buy Houdini 4 Aquarium, Houdini 4 PRO Aquarium, ChessOK Aquarium 2014 or any version of Chess Assistant 14 (including upgrade versions) and get online access to Lomonosov Tablebases until February 11, 2015 on http://tb7.chessok.com; you can also choose any program within $25/20 Euro range for free as a bonus!

Special Offer 2: Buy one of 3 packages available in the Combo Packages section of our shop: Complete Chess Strategy (Chess Strategy 3.0 + Chess Guide for Club Players + Chess Guide for Intermediate Players), Complete Chess Opening (Opening Lab + Encyclopedia of Opening Blunders + How to Win Miniatures at Chess) and Complete Attack on the King (Attack on the King I + Attack on the King II + Advanced Defense). Each of them contains 3 courses, but you only pay half the price if you order one of the packages while this offer is in effect!

Special Offer 3: Buy 1-year access to Lomonosov Tablebases at a 30% discount!

Special Offer 4: 20% off all products in the Beginners (DVD, download), Club Players (DVD, download), Intermediate Players (DVD, download), Modern Chess Opening (DVD, download) and Training Packages (DVD) sections.

Special Offer 5: If you order products for more than $120/€100, choose one download programs for up to $25/€20 each as a bonus!

Special Offer 6: Order any 2 programs in our web shop and get a 3rd program of your choice (within the price range of the first two) for free!

Special Offer 7: If you own ChessOK Aquarium 2012, buy ChessOK Aquarium 2014 and receive Chess Openings Encyclopedia 2014 (download) as a bonus! Put your Aquarium 2012 serial number in the comments field.

Note: Specify the bonus product(s) you want to receive in the comments field when filling the order form.

Chess King 4 for Mac!

The revolutionary Chess King 4 with Houdini 4 software is now available for Mac, offering Mac users the strongest chess engine and rich training options in a friendly shell!

Chess King 4 Deep Pro is a new and versatile tool for chess players and is an ideal introduction for the beginner, a challenging opponent for the practiced amateur, and an invaluable coach for the aspiring master.

Video Introduction to CT-ART 5.0

A short video introduction to our recently released product CT-ART 5.0 Complete Chess Tactics (DVD, download) is now available on its page in our shop.

The video introduces the courses included in the package and shows the features of the Peshk@ interface.

More videos are coming soon!

Chess Assistant Standard Released!

Chess Assistant Standard has been released!

If you only need an affordable yet robust database management tool for club and intermediate players, Chess Assistant Standard is your program of choice! Comes with integrated Chess Opening Encyclopedia 2014 and more than 6 million games.

This version does not include Houdini 4, Premium Game Service 2014 and Lomonosov Tablebases access, but has everything else Chess Assistant has to offer.

Check the comparison table to find the perfect software for your needs.

Online Access to 7-man Tablebases!

Our new service providing online access to 7-man Tablebases on tb7.chessok.com until July 1, 2015 is now online! Using this service, you can access the tablebases from any device via a web interface, without having to use the Aquarium or any other software.

Other new features include position sharing, free 6-man tablebases, forum, tablebase statistics, saving positions as favorites and more!

Lomonosov Tablebases allow you to determine if any position with 7 or less pieces leads to a draw or can be won by either side - with 100% certainty.

If the game can be won, the path with the least number of moves until the end of this variation is shown, given that both players make the best moves possible. If the losing player makes a suboptimal move, he will lose sooner and the program will display the new optimal path.

Free Game Service

Game Service: October, part 4. All updates are available on this page.

Lomonosov Tablebases Online Access

Online access to Lomonosov Tablebases is open! Visit the service now or learn more about Lomonosov Tablebases.

For now only owners of Chess Assistant 14, Houdini 4 Aquarium and ChessOK Aquarium 2014 can use the service.

Users of ChessOK Aquarium 2014, Houdini 4 Aquarium and Houdini 4 PRO Aquarium can also access the tablebases directly from the Aquarium interface.

Chess Tactics for Club and Intermediate Players!

The download version of a new course on chess tactics, Chess Tactics for Club and Intermediate Players, has been released. Chess Tactics for Club and Intermediate Players contains 230 teaching examples introducing you to typical chess combinations and 350 new exercises designed to develop your playing skills and reinforce the knowledge acquired. If you enjoy playing other games in your pastime, try going to www.piramind.com for a wide range of games. You can play chess on Android at some of the sites listed here.
Just like chess, you can also play other games online, like Craps, Blackjack, Baccarat, Poker and more. To find the latest blackjack software, visit www.downloadblackjack.com, a website specializing in gaming software clients and real money card games. We recommend you to visit Online Casinos Canada where you can read more about the types of games you can play online and learn the strategies for each game. Alternatively you can try some of these games for free at this Australian games site. For tutorials and training of free casino games, you should visit this website. Fans of free games should go to Goldenkudo.com as they have a dedicated section for this. The exercises in Chess Tactics for Club and Intermediate Players are classified according to more than 30 tactical methods and motifs.

7-man Lomonosov Tablebases provide deeper-than-ever insight into chess endgame.

Download weekly chess database updates (containing 2000+ games) with latest tournaments and games in PGN and Chess Assistant format.

Study chess online on our new dedicated website. There are many training courses and thousands of chess puzzles to solve.

More »

The Millionaire Chess open is held in Las Vegas each year but before you go find out all you need to know about Vegas Comps.

Playing chess is a fun, stimulating way to spend your time. Why not go a step further and bet on professional chess games? Take a look at the Gambling land website, with a list of the best bookmakers in the business. These sites offer bets on most international chess championships.