WinFSP is a framework for implementing custom file systems on Windows. It enables the creation of user-mode file systems that appear as standard disk drives or network shares to the operating system, allowing developers to implement file system logic in user space via a proxy architecture that avoids the need for custom kernel code.
A primary differentiator is its FUSE compatibility layer, which maps POSIX-based file system calls to native Windows requests. This allows existing file systems written for the FUSE API to be ported to Windows and Cygwin environments.
The project covers a wide range of capabilities, including asynchronous I/O processing, advanced metadata and security descriptor management, and volume lifecycle control. It supports local disk and network share mounting, as well as the mapping of remote cloud storage to local drives. Implementation is supported through language bindings for Go, Java, Python, and Rust.
The system provides native support for ARM64 architecture and includes tools for kernel-mode debugging and NTFS compatibility verification.