Indeed, availability for Zillions means nothing to me. I don't have it, and I don't intend to buy it.
It must be said that alternatives like Ai Ai, the Interactive Diagram or Jocly are not on par with it regarding playing strength. The ID and Jocly are written in JavaScript, which is much slower than naturally compiled languages like C. Both evolved from projects that primarily focused on the user interface, and don't use the most efficient code even by JavaScript standards. For the ID I did not care, as it was never intended to be of super-human strength. And especially the Jocly AI uses a very poor engine design for Chess (probably as a compromise to also work for entirely different games). Ludii I know absolutely nothing about.
ChessV is a strong engine, and in general stronger than Zillions. But it is not as versatile. The configurable multi-variant engines for WinBoard (Fairy-Max, Sjaak II, Nebiyu) are also much stronger than Zillions, and although perhaps somewhat more versatile than ChessV not very easy to configure.
Perhaps I should start a project for rewriting the AI of the Interactive Diagram in C, so it could be used as a strong engine in one of the available user interfaces (WinBoard or ChessV). It would be interesting to have Greg Strong's opinion on this.
Indeed, availability for Zillions means nothing to me. I don't have it, and I don't intend to buy it.
It must be said that alternatives like Ai Ai, the Interactive Diagram or Jocly are not on par with it regarding playing strength. The ID and Jocly are written in JavaScript, which is much slower than naturally compiled languages like C. Both evolved from projects that primarily focused on the user interface, and don't use the most efficient code even by JavaScript standards. For the ID I did not care, as it was never intended to be of super-human strength. And especially the Jocly AI uses a very poor engine design for Chess (probably as a compromise to also work for entirely different games). Ludii I know absolutely nothing about.
ChessV is a strong engine, and in general stronger than Zillions. But it is not as versatile. The configurable multi-variant engines for WinBoard (Fairy-Max, Sjaak II, Nebiyu) are also much stronger than Zillions, and although perhaps somewhat more versatile than ChessV not very easy to configure.
Perhaps I should start a project for rewriting the AI of the Interactive Diagram in C, so it could be used as a strong engine in one of the available user interfaces (WinBoard or ChessV). It would be interesting to have Greg Strong's opinion on this.