Mobile ad hoc networks (MANET) offer a convenient basis towards pervasive computing, due to inherent support for anytime, anywhere network access for mobile users. However, the development of applications over MANET still raises numerous challenges. One such challenge relates to accommodating the high dynamics of the network's topology. Group management appears as a promising paradigm to ease the development of distributed applications over dynamic, mobile networks. Specifically, group management takes care of assembling mobile nodes that together allow to meet target functional and nonfunctional properties, and of further making transparent failures due to the mobility of nodes. Various solutions towards group management over MANET have been investigated over the last couple of years, each targeting specific applications. Building upon such an effort, this paper introduces the design and implementation of a group service for MANET, which is generic with respect to the various attributes of relevance. Generic group management allows supporting various applications, as illustrated through groups dedicated to mobile collaborative data sharing.