Girih is a modeling toolkit for geometric patterns, specifically Islamic Geometric Pattern, IGP.
The method used in developing this toolkit is based on formal grammar and string rewriting system. It uses letters and symbols to generate a formula for each pattern, instead of geometrical drawing solutions. Anyone who has the formula can generate the patterns that it represents.
The toolkit includes tools to model particular class of patterns without referring to their original drawing methods. In addition, a pattern library is provided to give direct access to the formula of a few of famous patterns. The current version so far covers 5-fold class, which includes Kond, Tond and one Shol pattern.