Apache Fluo (incubating) is an open source implementation of Percolator (which populates Google's search index) for Apache Accumulo. Fluo makes it possible to update the results of a large-scale computation, index, or analytic as new data is discovered.
Gfarm is a network shared filesystem and alternative to NFS, but optimized for reliability, scaling and access from wide area network. It can federate local disks of network-connected PCs and compute nodes in several clusters, and supports explicit replica location control by users. Plugins exist for FUSE, Zabbix, Hadoop, Samba, MPI-IO, GridFTP, and a Linux kernel module is under development.