XtreemFS is an object-based, distributed file system for wide area networks.

[1] XtreemFS' outstanding feature is full (all components) and real (all failure scenarios, including network partitions) fault tolerance, while maintaining POSIX file system semantics.

Fault-tolerance is achieved by using Paxos-based lease negotiation algorithms and is used to replicate files and metadata.

SSL and X.509 certificates support make XtreemFS usable over public networks.

The 1.0 release includes support for read-only replication with failover, data center replica maps, parallel reads and writes, and a native Windows client.