Uno DOS is a family of graphical operating systems. It began as a GUI-first, 16-bit real-mode OS written entirely in x86 assembly, fitting a kernel, window manager, two filesystems, cooperative multitasking and a full application set on a single 1.44 MB floppy. It has since grown into a contract-driven family of ports spanning home computers, consoles, handhelds, single-board computers and a phone. Its flagship is now pc64: Uno DOS running bare-metal on any modern 64-bit PC, on its own drivers, with its own network stack, browser, office suite, compiler and hypervisor.

Prebuilt images for every platform are on the releases page: a hybrid ISO and USB disk image for modern PCs, cartridge ROMs for the consoles and handhelds, disk images for the home computers, and SD-card payloads for the boards. Most run in an emulator within a minute; the user manual walks through booting real hardware, including one-click USB flasher apps for Windows and macOS. PLATFORMS.md is the ledger that answers what has been verified: per platform, what has booted on real hardware, what is emulator-verified only, and every known gap.

Uno DOS pc64 boots bare-metal on essentially any x86-64 PC made since ~2007. The shell is built on unoui, with a windowed desktop, taskbar, virtual desktops, window snapping, and an animated Alt-Tab switcher. Ten themes are live-switchable, from Aurora to faithful retro looks like Mac OS 7, Windows 3.1, and Amiga Workbench. Applications include Uno Word, Uno Calc, Uno Show (Office 97-class suite reading .doc, .xls, .ppt), a browser with HTML and TLS 1.2 HTTPS, Studio IDE, Micro Python, and a native SSH client.

Everything below the firmware line is native, written for this tree: storage (AHCI, NVMe, USB mass storage), USB polled host stack, and networking (Intel e1000, Realtek r8169). Uno DOS runs entirely on its own drivers, with a native FAT16/FAT32 driver and GPT/ESP authoring.