although it calculates this automatically for each display. Windows 8.1 prevents a user from forcibly enabling DPI virtualization of an application. Therefore, if an application wrongly claims to be DPI-aware, it will look too small on high-DPI displays in 8.1, and a user cannot correct that. Windows 10 adds manual control over DPI for individual monitors. In addition, Windows 10 version 1703 brings back the XP-style GDI scaling under a "System (Enhanced)" option. This option combines GDI+'s text rendering at a higher resolution with the usual scaling of other elements, so that text appears crisper than in the normal "System" virtualization mode. Android Since Android 1.6 "Donut" (September 2009) Android has provided support for multiple screen sizes and densities. Android expresses layout dimensions and position via the density-independent pixel or "dp" which is defined as one physical pixel on a 160 dpi screen. At runtime, the system transparently handles any scaling of the dp units, as necessary, based on the actual density of the screen in use. To aid in the creation of underlying bitmaps, Android categorizes resources based on screen size and density: X Window System The Xft library, the font rendering library for the X11 system, has a dpi setting that defaults to 75. This is simply a wrapper around the FC_DPI system in fontconfig, but it suffices for scaling the text in Xft-based applications. The mechanism is also detected by desktop environments to set its own DPI, usually in conjunction with the EDID-based family of Xlib functions. The latter has been rendered ineffective in Xorg Server 1.7; since then EDID information is only exposed to XRandR. In 2013, the GNOME desktop environment began efforts to bring resolution independence ("hi-DPI" support) for various parts of the graphics stack. Developer Alexander Larsson initially wrote about changes required in GTK+, Cairo, Wayland and the GNOME themes. At the end of the BoF sessions at GUADEC 2013, GTK+ developer Matthias Clasen mentioned that hi-DPI support would be "pretty complete" in GTK 3.10 once work on Cairo would be completed. As of January 2014, hi-DPI support for Clutter and GNOME Shell is ongoing work. Gtk supports scaling all UI elements by integer factors, and all text by any non-negative real number factors. As of 2019, Fractional scaling of the UI by scaling up and then down is experimental. Other Although not related to true resolution independence, some other operating systems use GUIs