Acrossfilesystem

Acrossfilesystem is a cross-filesystem abstraction layer and runtime library that provides a uniform interface for performing file and directory operations across diverse storage backends, including local disks, network shares, and cloud object stores. The project aims to decouple applications from filesystem specifics, allowing code to manipulate paths, metadata, and streaming data without hidden platform quirks.

It exposes a virtual filesystem API layered on a pluggable backend system. Each backend implements operations such as open, read, write, stat, mkdir, and rename; a central VFS middleware handles path resolution, normalization, and translation of permissions and ownership between backends. The project supports streaming, atomic operations, metadata caching, and Unicode normalization. It can be extended with new backends for additional storage types and protocols.

Backends typically include local disks, NFS/SMB network shares, and cloud stores using object APIs. Acrossfilesystem integrates with common user-space filesystem interfaces such as FUSE on Unix-like systems and Dokan on Windows to present a consistent mount point or API surface to applications.

It is suitable for backup and synchronization tools, cross-platform applications that run against multiple storage backends, and data migration utilities that must traverse heterogeneous environments.

Initiated as an open-source initiative in the mid-2010s, Acrossfilesystem evolved through community contributions to provide a portable, vendor-agnostic FS abstraction. License and governance are project-dependent.