Why Microsoft’s exFAT is finally coming to Linux – What it means for you

exFAT Overview

exFAT (Extended File Allocation Table) is a Microsoft file system designed for flash storage, supporting files larger than 4 GB and widely used on USB drives, SD cards, smartphones and other removable media.

Proprietary status and Linux support

Before 2019 the format was proprietary. Linux users relied on third‑party tools such as fuse‑exfat or exfat‑fuse, which raised stability and licensing concerns.

Microsoft open‑specification and kernel integration

In August 2019 Microsoft published the exFAT technical specification and granted permission for native implementation in the Linux kernel. The driver was merged in Linux 5.4 (released November 2019) and is built‑in by default.

Typical usage after kernel support

# Verify the driver is available
modinfo exfat

# Mount an exFAT partition
sudo mount -t exfat /dev/sdX1 /mnt/exfat

Patent protection via Open Invention Network (OIN)

Microsoft joined OIN in 2018. Contributions that implement exFAT in the kernel are covered by OIN’s defensive‑patent commitments, shielding contributors from patent litigation. OIN’s member base exceeds 3 000 organizations, providing a broad defensive patent pool.

References

Official exFAT specification: https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification

TechCrunch article: https://techcrunch.com/2019/08/28/microsoft-wants-to-bring-exfat-to-the-linux-kernel/

VentureBeat article: https://venturebeat.com/2019/08/28/microsoft-wants-its-exfat-file-system-in-the-linux-kernel/