Orca – A high-performance crossword grid filler

Orca is a fast crossword grid filler written in Rust that can efficiently fill gnarly, unconstrained grids. The link explains the algorithm in detail.

As a crossword constructor myself, I'm fascinated by wide open grids with very few black squares. But filling them is computationally difficult - almost intractable on existing software. Orca is multiple orders of magnitude faster in many such cases.