  Recent studies on the chiral order of regularly frustrated XY magnets are
reviewed both in classical and quantum cases. In the classical case, chiral
transition is a thermal one, while in the quantum case, it is a quantum phase
transition. Importance of spatial dimensionality on the chiral order is
clarified. Particular attention is paid to the possible ``spin-chirality
decoupling'' phenomenon, and to the possible pure chiral phase of either
thermal or quantum origin where the chirality exhibits a long-range order
without the standard spin order.
