Code Quality Rank: L1
Programming language: Rust
License: BSD 2-clause "Simplified" License

v86 alternatives and similar modules

Based on the "Miscellaneous" category.
Alternatively, view v86 alternatives based on common mentions on social networks and blogs.

Do you think we are missing an alternative of v86 or a related project?

Add another 'Miscellaneous' Module


Join the chat at https://gitter.im/copy/v86 or #v86 on irc.libera.chat

v86 emulates an x86-compatible CPU and hardware. Machine code is translated to WebAssembly modules at runtime in order to achieve decent performance. Here's a list of emulated hardware:

  • An x86-compatible CPU. The instruction set is around Pentium III level, including full SSE2 support. Some features are missing, in particular:
    • Task gates, far calls in protected mode
    • Some 16 bit protected mode features
    • Single stepping (trap flag, debug registers)
    • Some exceptions, especially floating point and SSE
    • Multicore
    • 64-bit extensions
  • A floating point unit (FPU). Calculations are done using the Berkeley SoftFloat library and therefore should be precise (but slow). Trigonometric and log functions are emulated using 64-bit floats and may be less precise. Not all FPU exceptions are supported.
  • A floppy disk controller (8272A).
  • An 8042 Keyboard Controller, PS2. With mouse support.
  • An 8254 Programmable Interval Timer (PIT).
  • An 8259 Programmable Interrupt Controller (PIC).
  • Partial APIC support.
  • A CMOS Real Time Clock (RTC).
  • A generic VGA card with SVGA support and Bochs VBE Extensions.
  • A PCI bus. This one is partly incomplete and not used by every device.
  • An IDE disk controller.
  • An NE2000 (8390) PCI network card.
  • A virtio filesystem.
  • A SoundBlaster 16 sound card.


Arch Linux โ€” Damn Small Linux โ€” Buildroot Linux โ€” ReactOS โ€” Windows 2000 โ€” Windows 98 โ€” Windows 95 โ€” Windows 1.01 โ€” MS-DOS โ€” FreeDOS โ€” FreeBSD โ€” OpenBSD โ€” 9front โ€” Haiku โ€” Oberon โ€” KolibriOS โ€” QNX


Here's an overview of the operating systems supported in v86:

  • Linux works pretty well. 64-bit kernels are not supported.
    • Damn Small Linux (2.4 Kernel) works.
    • All tested versions of TinyCore work.
    • Buildroot can be used to build a minimal image. humphd/browser-vm and darin755/browser-buildroot have some useful scripts for building one.
    • SkiffOS (based on Buildroot) can cross-compile a custom image.
    • Archlinux works. See [archlinux.md](docs/archlinux.md) for building an image.
    • Debian works. An image can be built from a Dockerfile, see [tools/docker/debian/](tools/docker/debian/).
    • Ubuntu up to 16.04 works.
    • Alpine Linux works.
  • ReactOS works.
  • FreeDOS, Windows 1.01 and MS-DOS run very well.
  • KolibriOS works.
  • Haiku works.
  • Android x86 1.6-r2 works if one selects VESA mode at the boot prompt. Newer versions may work if compiled without SSE3. See #224.
  • Windows 1, 3.0, 95, 98, ME and 2000 work. Other versions currently don't (see #86, #208).
    • In Windows 2000 and higher the PC type has to be changed from ACPI PC to Standard PC
  • Many hobby operating systems work.
  • 9front works.
  • Plan 9 doesn't work.
  • QNX works.
  • OS/2 doesn't work.
  • FreeBSD works.
  • OpenBSD works with a specific boot configuration. At the boot> prompt type boot -c, then at the UKC> prompt disable mpbios and exit.
  • NetBSD works only with a custom kernel, see #350.
  • SerenityOS works.

You can get some infos on the disk images here: https://github.com/copy/images.

How to build, run and embed?

You need:

  • make
  • Rust with the wasm32-unknown-unknown target
  • A version of clang compatible with Rust
  • java (for Closure Compiler, not necessary when using debug.html)
  • nodejs (a recent version is required, v16.11.1 is known to be working)
  • To run tests: nasm, gdb, qemu-system, gcc, libc-i386 and rustfmt

See [tools/docker/test-image/Dockerfile](tools/docker/test-image/Dockerfile) for a full setup on Debian or WSL.

  • Run make to build the debug build (at debug.html).
  • Run make all to build the optimized build (at index.html).
  • ROM and disk images are loaded via XHR, so if you want to try out index.html locally, make sure to serve it from a local webserver. You can use make run to serve the files using Python's http module.
  • If you only want to embed v86 in a webpage you can use libv86.js. For usage, check out the [examples](examples/). You can download it from the release section.

Alternatively, to build using docker

  • If you have docker installed, you can run the whole system inside a container.
  • See tools/docker/exec to find Dockerfile required for this.
  • You can run docker build -f tools/docker/exec/Dockerfile -t v86:alpine-3.14 . from the root directory to generate docker image.
  • Then you can simply run docker run -it -p 8000:8000 v86:alpine-3.14 to start the server.
  • Check localhost:8000 for hosted server.


The disk images for testing are not included in this repository. You can download them directly from the website using:

wget -P images/ https://k.copy.sh/{linux.iso,linux4.iso,buildroot-bzimage.bin,openbsd-floppy.img,kolibri.img,windows101.img,os8.img,freedos722.img}

Run all tests: make jshint rustfmt kvm-unit-test nasmtests nasmtests-force-jit expect-tests jitpagingtests qemutests rust-test tests

See [tests/Readme.md](tests/Readme.md) for more infos.

API examples

  • [Basic](examples/basic.html)
  • [Programatically using the serial terminal](examples/serial.html)
  • [A Lua interpreter](examples/lua.html)
  • [Two instances in one window](examples/two_instances.html)
  • [Saving and restoring emulator state](examples/save_restore.html)

Using v86 for your own purposes is as easy as:

var emulator = new V86Starter({
    screen_container: document.getElementById("screen_container"),
    bios: {
        url: "../../bios/seabios.bin",
    vga_bios: {
        url: "../../bios/vgabios.bin",
    cdrom: {
        url: "../../images/linux.iso",
    autostart: true,

See [starter.js](src/browser/starter.js).


v86 is distributed under the terms of the Simplified BSD License, see [LICENSE](LICENSE). The following third-party dependencies are included in the repository under their own licenses:

  • [lib/softfloat/softfloat.c](lib/softfloat/softfloat.c)
  • [lib/zstd/zstddeclib.c](lib/zstd/zstddeclib.c)
  • [tests/kvm-unit-tests/](tests/kvm-unit-tests)
  • [tests/qemutests/](tests/qemutests)


More questions?

Shoot me an email to [email protected]. Please report bugs on GitHub.


Fabian Hemmer (https://copy.sh/, [email protected])

*Note that all licence references and agreements mentioned in the v86 README section above are relevant to that project's source code only.