btrfs

WinBtrfs is a driver for Windows that lets the operating system read and write drives formatted with Btrfs, a filesystem type that is standard in many Linux environments. By default, Windows cannot see Btrfs-formatted partitions at all. With this driver installed, those drives appear and work like any other Windows disk. The driver is a complete reimplementation written from scratch and contains no code borrowed from the Linux kernel.

The project supports most of the significant capabilities that Btrfs offers on Linux. This includes several RAID configurations, which are ways of spreading data across multiple drives for redundancy or speed, from simpler setups like RAID0 and RAID1 through more complex ones like RAID5 and RAID6. It also supports three types of compression for storing data more compactly, disk health checks through scrubbing, the ability to create snapshots and subvolumes, and sending or receiving subvolume data between systems.

On the access control side, the driver maps between Linux-style user identifiers and Windows-style identifiers so that file permissions carry over correctly. It also supports Windows Subsystem for Linux, allowing WSL to use a Btrfs volume and preserve Linux metadata like permissions and symlinks. A Windows shell extension integrates with File Explorer so you can create subvolumes and snapshots through right-click menus without using the command line.

Installation is straightforward: download the release, right-click the included .inf file, and choose Install. The driver is signed so it loads without special configuration on most systems. It is also available through the Chocolatey and Scoop package managers. For Secure Boot users, a registry change may be needed, though the README suggests turning Secure Boot off as the simpler option.

The driver is released under the GNU Lesser General Public Licence. The README includes a clear disclaimer that you use it at your own risk and should keep backups of any data on the drives you mount through it. It has been in development long enough to cover most day-to-day use cases, but a few features such as defragmentation and quota support are still noted as not yet implemented.