Bismaleimides (BMIs) belong to the class of thermosetting resins, also called addition polyimides. Introduced in the late 1960s, they have found numerous applications as matrix resins for high-performance, heat-resistant composites, adhesives, and coatings. The chemical composition of formulated BMI resins varies widely in order to meet stringent requirements being imposed upon mechanical and electrical properties of advanced composites. However, modifications are also necessary to meet the processing characteristics of both established and emerging composite manufacturing processes, sometimes at the expense of the resin properties. In this short review, modern approaches to the formulation and processing of heat-resistant bismaleimide resins are briefly discussed.