Most commercial chess computer programs are only available for Windows. One exception is Shredder, the chess engine by Stefan Meyer-Kahlen that won the World Computer Chess Championship several times is now also available for Linux and Macs. I am using free software running Linux almost exclusively since more than 10 years and got curious on what I miss in the world of commercial chess software. Therefore, I gave ShredderLinux a try. There are currently 3 different Shredder versions available for Linux: Shredder Classic, Shredder 9, and Deep Shredder 9. Shredder Classic is based on an older and slightly weaker version of the engine but has the advantage that a free 30-day trial version is available for download. Shredder 9 provides a stronger version and Deep Shredder is optimized to take full advantage of multi processor machines. The Linux versions come with the chess engine itself and a java-based graphical user interface.

Java user interface of Shredder 9 Linux

I use computer chess engines for two purposes: 1) for analyzing chess games and 2) as sparring partner. For analyzing games, it is indeed desirable to use the strongest available software to make sure that the best possible moves can be found. But in many cases it is heplpful to see not only the very best move but also alternatives. Shredder is able to calculate several variations for this purpose, which is an advantage compared to most freely available chess engines that to the best of my knowledge do not provide this feature. The Shredder chess engine can also be used together with third-party tools, such as the chess database Scid. The web site Shredder for Linux provides useful information on using Shredder with other programs such as a variety of graphical user interfaces/chessboards.

As mentioned before, any modern chess program is a much stronger chess player than me and also than the majority of my opponents. Most importantly, chess engines are extremely strong in tactics. Most beginner-level chess games are decided by tactical mistakes. To make a chess engine an effective sparring partner, it has to emulate human behavior by making occasional tactical mistakes. This way, it is possible to learn how to exploit these mistakes. My current sparring partner, the free chess engine Phalanx has so-called easy settings that try to emulate human mistakes. Reducing the strength of Shredder is even easier because it allows to set the program's approximate playing strength between 1000 ELO and maximum strength. A quick game example of Shredder playing white with reduced strength against me can be found here. I managed to drop a piece in move 8 and missed a few tactical opportunities that Shredder presented to me. But to my own surprise, I managed to exploit Shredders total neglect of defense (seems the computer felt bad for me) and ultimately won by checkmate. Compared to Phalanx, Shredder's response to my moves feel more natural which may be due to the prolonged "thinking" time the program takes for making a move.

Are there other commercial chess engines with native Linux support? Fruit is another strong professional chess engine that is available for Linux. However, it has currently no straightforward settings to reduce the playing strength and comes without graphical user interface. Compared to their windows counterparts, the native Linux versions have slightly reduced features. For instance, the Java-based user interface of Shredder 9 for Linux (see full-size screenshot) does not provide a 3 dimensional view of the chess board and more importantly also misses the sophisticated endgame tablebase features of the Windows version. Nevertheless, the price tag is the same for both Linux and Windows versions. Overall I can recommend Shredder Linux for people who want to have a very strong chess engine or simply want to play some fun games against the computer because games with the reduced strength setting feel more human-like and fun than against the free chess engines. The few technical problems I had with Shredder were solved by their email support. A notable advantage of the small size of the business selling Shredder Chess is that Shredder's creator himself takes personally care of the support. Most other application needs, however, can be fulfilled by its free counterparts such as Crafty and Phalanx.

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yes!
written by frank fernandis, April 26, 2007

This chess engine has the same chess knowledge as Shredder 9 Linux and Deep Shredder 9 Linux, but its calculations are not as fast and efficient.

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written by Ben parker, August 20, 2007

Well yes frank i agree,however it is not upto the mark in mines views.

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written by Paaul anderson, September 11, 2007

This in turn will attract more users to Linux and as time passes Microsoft could get some healthy competition.

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written by Sciurus, September 11, 2007

Paul:
I would hope that more companies start developing for Linux or even cross-platform. However, the last time I looked at the Shredder website, the Linux versions were still stuck at Shredder 9 even though Shredder 10 for Win$ has been published a long time ago.

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written by Fingerfehler, October 28, 2007

Deep Shredder 11 Linux is out, although it appears that the engine is 32-bit only,while the Win$ has both 32 and 64-bit engines
Also needs a proper desktop intergration with gtk or qt interface, java isn't really good enough. We as linux users should demand parity with Win$
for paying the game price !

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written by Fingerfehler, October 28, 2007

"same price"

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written by Sciurus, October 28, 2007

Hey Fingerfehler, thanks for letting me know! According to the Shredder website, Shredder 11 is significantly stronger than the older version. However, I don't really see a reason for me to spend money on an update - Shredder 9 is good enough for me.

At least, the Linux version seems now to include the access to the extensive online databases Shredder offers. So I guess the Linux version gets closer in features to the Win$ version.

I agree, same money should mean same features. However, almost all commercial Linux software offers less on the GUI side than the Win$ counterpart. Well, at least we did not have to pay money for the OS...

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written by Fingerfehler, October 29, 2007

Don't get me wrong,Stefan is to be commended for producing the "Deep" version. But appearance and functionality are just as important to us non-Win$ users.
Without constructive criticism on our part, things are not going to improve.

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written by Sciurus, October 29, 2007

I agree that without criticism there won't be improvement. However, personally I mostly use just the engine for analysis in SCID-PG. Thus the GUI is not a big deal to me. But of course there is the big question if selling just the engine is a good business model. To my knowledge, Rybka is only sold as engine without GUI but I guess the big mass of users wants something that just works out of the box without the need for other software.

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written by Thomas, December 22, 2007

Yeah, Shredder is very nice.
However I don't think the engine is much stronger than Glaurung or Fruit, which are free and can be used with free, more integrated, linux interfaces such as PyChess: http://pychess.googlepages.com

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written by Ralph, August 13, 2008

Thanks for posting this information. I'm a big chess and Linux fan, and I'm definitely going to check this software out.

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