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 August 22 to August 28, the following special offers are available on ChessOK.com. All offers stack!

Special Offer 1: All products in the Training Packages (download) section of our shop receive a 40% discount!

Special Offer 2: 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 3: Buy 1-year access to Lomonosov Tablebases at a 30% discount!

Special Offer 4: 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 5: 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 6: If you order products for more than $120/€100, choose one download programs for up to $25/€20 each as a bonus!

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.

Chess Tactics in Scandinavian Defense Released!

Another course for our Chess Tactics in the Opening series is released! Meet Chess Tactics in Scandinavian Defense.

Scandinavian Defense is a daring opening for those who fight for initiative from the very first moves. Many strong chess players used it as Black, including the world championship match between Anand and Kasparov in 1995.

The course presents a deep theoretical and practical overview of the actual variations. More than 260 new exercises!

In addition to this, our Chess Tactics in the Opening pack is now updated to 10 courses. You can buy all the courses of this series for almost half the price!

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.

Free Game Service

Game Service: August, part 3. All updates are available on this page.

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.

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