>>But I don't want to buy it. I did not! There is a free version (very limited), that, while being limited, gives some flavour :) >>By the way: I've bought ChessBase 11, I need it only for test reasons, >>for the development of the decoder. This database application, a very >>expensive product, is really lousy, I cannot see a real practical value, >>and it cannot give a real flavour, and that's the thing with most >>proprietary software. (The price was 200 Euro. Last year ChessBase 12 >>has been released, the price for the upgrade from version 11 to version >>12: 200 Euro. This is a kind of trickery, it's frustrating to buy software, >>and I didn't buy the upgrade.) Frankly, I don't have the foggiest idea about how software market works, and how on the earth such products (e.g., Chessbase) can be so dominant.... >>I've found two ones: http://www.chesspositiontrainer.com/index.php/en/ http://innokuo.altervista.org/chesshero.html I knew the latter, but it seems only for Windows, so I did not try it. I will check out the former, even though it does have the same "trick" (limited free version, full version not free). >>But i didn't try any of them, the development of Jessy has not yet >>started, at first the alpha version of Scidb has to be released. [...] >>For such functionalities another project is in planning stage: Jessy (but >>probably not for chess training). In this way an overloading of the >>database application Scidb will be prevented. I already knew this story, but thanks again for the explanation. Choices regarding the software architecture are yours, of course. If I may tell you my opinion, I kind of disagree on the "overloading" issue, but whether the functionality are contained in only one, or they are splitted in 2-3 programs, what matters is that it (they) is (are) well designed.Regarding the training, I disagree too: an application designed to interact with chess engines fits very well to chess training. Cheers