In the introduction, some of the applications of the A(III)B(V) compounds are indicated. Their limitations are mentioned and two possibilities are suggested for overcoming these. In view of the A(III)B(V) compounds' outstanding contribution in recent years, the investigation of their isoelectric analogues, the A(II)B(IV)C(2)(V) compounds, is suggested as a logical step. CdSnAs(2) is shown to be the most investigated compound in this group, although several phosphides have potentialities as materials with energy gaps in the visible region of the spectrum. A comprehensive bibliography of the published work on A(II)B(IV)C(2)(V) compounds is given.