The open research wiki of the Eternity II community: why the puzzle is so hard, everything you need to build a solver, and the researchers' open notebooks: records, methods, experiments and dead ends, all sourced and reproducible.
This wiki is a work in progress: the site is young and slowly absorbing years of community research. If something you know is missing, the mailing list below is the right place to say so.
This wiki is for the people who want to actually solve it. Everyone who has attacked Eternity II took one of nine roads, from modelling why it resists, through pruning the search and building boards up, to throwing hardware at the wall. Pick the road you care about; each opens onto everything the wiki knows about it, drawn from the theory, the solver-building guides, and the lab notebook alike.
Prefer to browse by reading mode rather than by method? The wiki splits four ways:
The design that was tuned to resist cleverness, and the structural walls (rigidity, entropy, forbidden patterns) that explain the gap between the best known board and a full solution.
Validation data, the literature ranked by usefulness, the methods behind the records, the dead ends, and how to run the code yourself.
The open notebook: structural findings and the named search experiments built to attack the puzzle, each credited to its author and reproducible from source.
The record and the people behind it: two decades told as a story, the record boards themselves, the record-holders and theorists, and the papers.
Or browse by method instead: the nine roads in the left rail are each a hub gathering every article on that theme.
Two lookups you will reach for again and again while reading or building:
The exact counts (pieces, colours, edges) to check your own edge-matching and constraint code against.
Every term the wiki leans on, defined once: community jargon, the loaded computer-science words, and the notation the boards are written in.
The story of the puzzle, its records and the people who chased them now live together under History & community.
The research conversation lives in a few long-standing places:
Jef Bucas's GPL viewer; its URL format is the community's lingua franca (and this site speaks it natively).
An active server where puzzlers share their runs, records and code, in real time.
The active mailing list: records, techniques, and 15+ years of accumulated folklore.