I´ve used for chiral resolution by formation of diastereomeric salts (using benzoylated derivatives of TA), quenching LiAlH4 with NaK salt of TA, its used as a backbone of various chiral catalysts and ligands such as TADDOL derivatives, its used as an additive for Sharpless epoxidation.
Its also a suitable chiral building block for synthesis since it contains two stereocenters and the acids can be easily modified into other functional groups