macFUSE

macFUSE is a software framework that enables the creation and mounting of file systems in user space on macOS. It provides a FUSE-compatible API and the accompanying components that allow developers to implement a file system as a user-space program rather than in the kernel. The system includes a kernel-space component that integrates with the macOS Virtual File System layer and a user-space library that implements the FUSE protocol and handles input/output operations.

When a file system is mounted, the kernel component forwards operations such as read, write, getattr, and readdir to the corresponding user-space process, which performs the requested actions and returns results to the kernel. This architecture makes it possible to expose remote storage, encrypted data, or specialized data formats as regular files and directories within macOS.

macFUSE has a long history as the basis for FUSE on macOS. It originated from the MacFUSE project and has inspired and informed related implementations and forks, such as later macOS-specific FUSE ports. It is maintained as an open-source project and is widely used by developers and power users to access and build custom file systems on macOS. As macOS has updated security policies, macFUSE and related projects have adapted by offering alternatives and updated deployment methods to work with system extensions and modern kernel-extension policies.