Ziliang Guo uploaded ReactOS 0.4.1 to the official channels of the project as the first point release in the 0.4.0 series, bringing initial read/write support for the Btrfs file system by implementing the WinBtrfs driver directly into the OS. Among other noteworthy changes, ReactOS 0.4.1 improves the usability of the Shell by adding various fixes to the rendering of folder views and icons, enhances the built-in USB support, and introduces support for VM shared folders, which right now works with the Oracle VirtualBox and VMware Player apps.