Collecting hex grid resources for over 25 years. - Red Blob Games

Thanks to Codingame! for the link (during Coders of the Caribbean)

• Hexagonal Tiling Explained! - The Art of Code
• For hexagons, all neighbors are equidistant. / H3: Hexagonal hierarchical geospatial indexing system

see also

• H3: For indexing geographies into a hexagonal grid, by Uber