The family of MXenes has expanded since the discovery of chemical order in parent quaternary MAX phases, displaying either out-of-plane (o-MAX) or in-plane (i-MAX) order upon alloying. Through selective chemical etching of these materials, corresponding MXenes can be derived, with out-of-plane and in-plane ordering of elements, as well as with ordering of vacancies. Both o-MAX and i-MAX phases have increased the number of metals that can be incorporated in these laminated carbides and nitrides. Examples of realized MXenes with out-of-plane order are Mo2Ti2C3 and Mo2ScC2, and for in-plane ordering of vacancies, there are Mo1.33C and W1.33C. Their versatile chemistry shows a high promise for a range of applications, including energy storage and catalysis