Mobile ad-hoc networks are typically very dynamic networks in terms of available communication partners, network resources, connectivity, etc. Furthermore, the end-user devices are very heterogeneous, ranging from high-end laptops to low-end PDAs and mobile phones. Traditionally, middleware is used to abstract from this heterogeneity and to enable the application programmer to focus on application issues. We propose to develop middleware services that additionally provide services for information sharing in mobile ad-hoc networks, because the possibility to share information is mission critical for many mobile ad-hoc network applications.