Network-enabled server (NES) environments are valuable candidates to provide simple computing Grid access. These environments allow transparent access to a set of computational servers via Remote Procedure Call mechanisms. In this context, a challenge is to increase performances by decreasing data traffic. This paper presents DTM (Data Tree Manager), a data management service for NES environments. Based on the notions of data persistency and data replication, DTM proposes a set of efficient policies which minimize computation times by decreasing data transfers between the clients and the platform. From the end-user point of view, DTM is accessible through a simple and transparent API. We describe DTM and its implementation in the DIET (Distributed Interactive Engineering Toolbox) platform. We also present a set of experimental results which show the feasibility and the efficiency of our approach. Copyright c © 2007 John Wiley & Sons, Ltd.