Hi Gian-Carlo,
in the situation we have you can nothing do ... NOTHING without new efforts.
To ignore such engines like Robbolito (if RobboLito is a clone ... I missed so far the prof) will make the situation not better.
For commercial programmers, like you, is all very disappointed and I can understand it.
But I am sure you have your own loyally / faithfully customers.
With time more and more groups will be build. For sure also more as one group of persons which like clones, hacker software etc.. In five years we have 5 different groups of persons which like clones, hacker software. Perhaps 20 groups of hacker teams or more.
The group of persons which used such things must live with it. I have a clear conscience to buy for it.
I have the following opinion:
Programmers should have to guard his own ideas. GPL isn't the right way (see my answere today of a posting from Bob). If programmers don't guard his own ideas ... I think this group of persons have to life with clones and copies from the own ideas.
Very hard but reality !!
And for sure you know it too.
Not nice to see that cracks from Ruffian and Ktulu are a short time after release are available.
Example:
If Robbolito will run without crashes and ponder = on, why I should not tested this engine if I like the style. And why I should not buy Deep Sjeng if I like the work you do. I will buy your next version for sure because I like your engine too.
If I can see that a clone will give me fun and improvements (the programmer say ... my program based on ...) I will give the engine a chance (so far like Protector, Cyclone).
Not easy to see for users like me:
Which of the commercial and free programmers working honest. In your case I am sure ...
Different point of views:
The site of the users
The site of the commercial programmers
The site of the GPL persons
The site of the freeware programmers without free sources
The site of the persons which created a rating list.
and so on ...
The poll is interesting ... you can see which of the group have here the most members
For myself a very hard topic:
I gave many of my free time computer chess in the past. Nice to see that from my site many persons jump to chessbase to the freeware programmers and other interesting sites.
Try to power the commercials, the freeware selection and have bad experience with clones too.
Thinking on Leiden, Ruffian won ... you know.
Days before Vincent Diepeveen gave his statement: "Ruffian is a clone". Different sources sent PerOla to two persons. I read nothing ... sorry for my statement. OK, in this time your first commercial version are available too. I am sure you don't like to see that Ruffian will be available too. I am not thinking about it.
In all groups we can found black sheeps.
And for sure, not all what I do in the past for computer chess are right. I made often mistakes because I made to many things to the same time. And my opinion are not right in each case ... but I saw it later.
Let me have fun with Sjeng and your work you do for the others and me. And I hope you don't lose your interest on computer chess.
Best
Frank