Contributors. Introduction. Atomic-level geometry of crystalline interfaces; D. Wolf. Experimental investigation of internal interfaces in solids; D.N. Seidman. Bulk interfaces. Part I: Bulk interfaces. Correlation between the structure and energy of grain boundaries in metals; D. Wolf, K.L. Merkle. Grain and interphase boundaries in ceramics and ceramic composites; M.G. Norton, C.B. Carter. Special properties of E grain boundaries; G. Palumbo, K.T. Aust. Grain boundary structure and migration; D.A. Smith. Role of interfaces in melting and solid-state amorphization; S.R. Phillpot, S. Yip, P.R. Okamoto, D. Wolf. Wetting of surfaces and grain boundaries; D.R. Clarke, M. Gee. Part II: Semi-bulk and thin-film interfaces. Structural, electronic and magnetic properties of thin films and superlattices; A. Continenza, C.Li, A.J. Freeman. Surfaces and interfaces as studied by scanning-tunneling microscopy; R. Hamers. Epitaxy of semiconductor thin films; J. Batstone. Phase behavior of monolayers; S.G.J. Mochrie, D. Gibbs, D.M. Zehner. Elastic and structural properties of superlattices; M. Grimsditch, I.K. Schuller. Computer simulation of the elastic behavior of interface materials; D. Wolf, J. Jasczak. Interfaces within intercalation compounds; M.S. Dresselhaus, G. Dresselhaus. Nanophase materials: structure-property correlations; R.W. Siegel. Part III: Role of interface chemistry. Interfacial segregation, bonding and reactions; C.L. Briant. Physics and chemistry of segregation at internal interfaces; R. Kirchheim. Atomic resolution study of solute-atom segregation at grain boundaries: experiments and Monte Carlo simulations; S.M. Foiles, D. Seidman. Amorphization by interfacial reaction; W.L. Johnson. Relationship between structural and electronic properties of metal-semiconductor interfaces; R. Tung. Electronic properties of semiconductor-semiconductor interfaces and their control using interface chemistry; D.W. Niles, G. Margaritondo. Microscopic nature of metal-polymer interfaces; P.S. Ho, B.D. Silverman, S-L. Chiu. Part IV: Fracture behavior. Tensile strength of interfaces; A.S. Argon, V. Gupta. Microstructure and fracture resistance of metal/ceramic interfaces; A.G. Evans, M. Ruhle. Role of interface dislocations and surface ledges in the work of adhesion; D. Wolf, J. Jaszczak. Microstructural and segregation effects in the fracture of polycrystals; D.J. Srolovitz, W. Yang.