Are there tools to create opening books

[Uri Blass]

not based on previous games but based on engine analysis?

It can be done not only for the opening position but for every position and also for chess960 or other games.

The idea is that the engine analyze the root position with multi-pv and based on the scores generates a tree and based on the tree create an opening book when in the opening book it has only one option for white and many options for black or only one option for black and many options for white.

The tool does not have to use multi-pv and may use also function next best move in case that the engine support it.

[xr_a_y]

Should be quite easy to script.

[Ovyron]

Yeah, I think Aquarium's IDeA could do this, you'd just set the thing to Multi-PV and it'd generate the tree you want, and extend the lines automatically, and can be used as an opening book. It's commercial, though.