This review represents the fifth in the series of fundamental reviews on capillary electrophoresis (CE) appearing in the journal. This review, which covers the period from October 1995 to October 1997, focuses on significant developments in the theory and practice of CE. Following the previously successful format, included here are papers covering capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), capillary isotachophoresis (CITP), and capillary electrochromatography (CEC). Within these separation systems we emphasize advances in the underlying principles and theory including performance optimization, instrumental configurations (sample introduction, CEC, microchips, etc.), and detection strategies. Publications that appeared during the covered period in which the emphasis was on specific applications of CE have not been included in this review. These can be easily accessed through various numbers of existing application reviews (1) or applicationsspecific literature searches.The review is not intended to provide a comprehensive compilation of the more than 3600 CE papers published between October 1995 and October 1997. The author's intent, rather, was to gather and present those papers representing fundamental developments across the CE landscape. It is hoped that the result will provide a flavor for the current directions in which CE is evolving, where CE has matured, and perhaps offer insight to some of the latent, untapped, promise of CE.