FSter is a virtual filesystem implementation based on FUSE and exploiting Tracker's indexer to allow access to files according to the metadata with which they’re associated. Its behavior is highly customizable with XML configuration to describe in detail the desired hierarchy of files.
CarvFS is a user space FUSE filesystem aimed at computer forensic tools that process disk and/or memory dump images or other large data files. The filesystem allows CarvPath-aware tools to use CarvPath annotations as a way to designate partitions, files, alternate streams, processes etc. within a disk or memory image as a string, making them available trough the filesystem as a pseudo file that can be handed to other tools. This removes the need to copy the information out of the disk image and reduces storage requirements.
S3QL is a file system that stores all its data online. It supports Amazon S3, Google Storage, and OpenStack and effectively provides you with a hard disk of dynamic, infinite capacity that can be accessed from any computer with Internet access. S3QL provides a standard, full featured Unix file system that is conceptually indistinguishable from any local file system. Additional features include compression, encryption, data de-duplication, immutable trees, and snapshotting, which make it especially suitable for online backup and archiving. The design favors simplicity and elegance over performance and feature-creep. Care has been taken to make the source code as readable and serviceable as possible. Solid error detection, error handling, and extensive automated test cases are provided.
Gfarm is a distributed filesystem, generally used for large scale cluster computing. It's implemented in userland, and can be mounted by FUSE. It utilizes locality of a file to access a data node, and supports Globus GSI for Wide Area Network. Users can explicitly control file replica location on Gfarm. Gfarm can be used as an alternative storage system to HDFS for Hadoop, Samba, MPI-IO, and GridFTP. Monitoring via ZABBIX and Ganglia is also supported.