The library provides implementations of of fuzzy standard and intuitionistic sets, plain and dimensioned fuzzy numbers, fuzzy logic, plain and dimensioned linguistic variables, fuzzy sets of linguistic variables. Lattice operations are provided for truth values, sets, linguistic variables. Fuzzy numbers are implemented over both integer and real domains with standard arithmetic operations supported. Fuzzy logic is based on the intuitionistic fuzzy sets and the possibility theory. Fuzzy inclusion operations are defined in terms of fuzzy logical values. String oridented I/O and GTK+ widgets are supported.