We present a Scalable Distributed Information Management System (SDIMS) that aggregates information about large-scale networked systems and that can serve as a basic building block for a broad range of large-scale distributed applications providing detailed views of nearby information and summary views of global information. To serve as a basic building block, a SDIMS should have four properties: scalability to many nodes and attributes, flexibility to accommodate a broad range of applications, support administrative autonomy and isolation, and robustness to node failures and disconnections. We design, implement and evaluate a SDIMS that (1) uses techniques from Distributed Hash Table (DHT) literature to create scalable aggregation trees, (2) provides flexibility through a simple API that lets applications control propagation of reads and writes, (3) provides autonomy and isolation through simple augmentations of current DHT algorithms, and (4) is robust to node and network reconfigurations through lazy reaggregation, on-demand reaggregation, and tunable spatial replication. Through extensive simulations and micro-benchmark experiments, we observe that our system is an order of magnitude more scalable than existing approaches, achieves autonomy and isolation properties at the cost of modestly increased read latency in comparison to flat DHTs, and gracefully handles failures.