Abstract <p>The review considers Heusler alloys that exhibit unique functional properties, such as shape memory and magnetocaloric effects. Particular attention is paid to Heusler alloys, in which half-metallic ferromagnetism and spin-gapless semiconductivity are realized. These compounds that are “ordinary” from the point of view of the crystal structure, exhibit unusual kinetic and magnetic properties due to the features of their electronic structure and magnetic state. Their magnetic and transport characteristics are highly sensitive to external influences. Depending on the alloy composition and external parameters, transitions between the states under consideration can occur. This opens up further prospects for controlling the electronic and magnetic properties of Heusler alloys and their potential applications in fields, such as spintronics and micro- and nanoelectronics.</p>