This paper presents a middleware platform that supports the provision of services in disconnected MANETs. This kind of MANET shows specific mobility, volatility and density characteristics that lead to the absence of end-to-end connectivity and thus to the fragmentation of the network. The presented platform exploits content-based communications (through a publish/subscribe paradigm) and follows a store-carry-and-forward approach for the network-wide opportunistic dissemination of messages. Service discovery and invocation are implemented on top of these communication features. The paper first describes the two layers of the platform and then gives simulation results obtained when evaluating the discovery and invocation satisfactions as well as the network load in a realistic scenario.