Leela

Leela is a Go playing program that combines a strong engine with a small, easy‑to‑use graphical interface. It supports multiple processors and GPU acceleration, offering strength up to 9 dan on a standard 19 × 19 board and adjustable board sizes up to 25 × 25. The interface lets users set playing levels, handicap, komi, and choose between fixed‑strength or time‑based difficulty, while also handling Chinese rules with positional superko and SGF file import/export.

The software includes analysis tools that display critical variations, winning odds, territory estimates, and best lines, and it can auto‑adjust difficulty in rated game mode. Its deep learning core uses a convolutional neural network trained on millions of professional positions, providing more human‑like play and improved strength, especially when GPU acceleration is available.

Leela is distributed for macOS, Windows, Ubuntu, Arch/Manjaro, and Fedora, with both graphical and command‑line versions, and the source code is hosted on GitHub. It is positioned as a stable, free introduction to Go for users who want both casual play and detailed analysis.