Morpion Solitaire

A fast player and solver. Play the four standard variants in your browser, hunt records with several search engines (NRPA, large-neighbourhood perturbation, exhaustive), and read or write MSR — a self-describing record format meant to supersede Pentasol.

The 5T world record is 178; 4T (62) and 4D (35) are solved. The web build runs multi-threaded WebAssembly. Free software — the app is GPL-3.0-or-later, the msr format library is MIT OR Apache-2.0.