Electrophilic carbenes accept a variety of n‐ and π‐donors. The products range from persistent ylides to matrix‐isolated xenon complexes. Ylides can be viewed as carbene complexes if they regenerate carbenes thermally or undergo concerted methylene transfer reactions. According to these definitions, the present review focuses on oxonium and iodonium ylides. Transient π‐complexes appear to be involved in addition reactions of carbenes with arenes (but not with alkenes). Nucleophilic carbenes form adducts with Lewis acids which are, for the most part, stable and have been well characterized structurally. Only recently attention has been directed to reversible systems. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)