Open Source MS-DOS Operating System Kernels

FreeDOS is an open source DOS-compatible operating system that you can use to play classic DOS games, run legacy business software, or write new DOS programs. Any program that works on MS-DOS should also run on FreeDOS.

DOS/32 Advanced DOS Extender is a drop-in replacement for the DOS/4GW DOS Extender and compatibles. Being fast, small and flexible DOS/32A can be used in many environments, from embedded systems to DOS emulators, by both developers and end users alike.

Public Domain Operating System (currently x86 and 80386 and S/370 and S/390). Note that latest source code is here in git, but latest executables and packaged source are at http://pdos.org

vmdos runs FreeDOS in virtual-8086 mode under a small 32-bit protected-mode kernel. It boots from GRUB (BIOS or UEFI) or as a UEFI application kernel. The kernel emulates the BIOS and PC hardware that DOS touches, so FreeDOS's kernel and FreeCOM run unmodified. Drive C: is the FAT partition of the boot disk (SATA/AHCI, IDE, NVMe, virtio or USB), so changes and saved games persist. A RAM disk is available as fallback. Ready-made USB images are provided in the releases. Features include: • VGA text + graphics (mode 13h, Mode X, VBE) scaled to modern displays (sharp / smooth / xBRZ) • Sound (PC Speaker, Sound Blaster, AC'97, HD Audio, USB Audio) • Network (packet driver + IPX) on many Ethernet chips • Mouse, keyboard, CD/ISO support • Optional hardware virtualization (VMHV) for programs that need real mode ownership • Bootable USB stick that becomes drive C:

This site will be a gift to MenuetOS, a 32 bit assembly coded operating system from Finland, Russia and Hungary.

DOS-C Kernel is an MS-DOS compatible kernel and the original FreeDOS kernel.

A distribution of FreeDOS which strives for Ease-Of-Use and Stability, aiming to offer a regular release schedule, utilizing the wide range of DOS-APPS available.

This is GIMI, the Graphical Interfaced Multitasking Interpreter. One of the few GUIs made in QuickBASIC featuring multitasking. This one has its own script language for making programs, damm fast SVGA modes, lots of programs, and more!

RMF-DOS is a project to create a compact, 8086-compatible, free clone of MS-DOS.

Sensa is not an operating system, is a work environment compatible with Android © 4.4.4, Firefox OS ©, Linux Ubuntu 12.12 ©, MacOS Classic 7 ©, MS -DOS © operating systems, and Microsoft Windows 8.1 ©; whose distribution is free, and with source code available under GNU GPL 2.0 license .

The Vortex project consists of 2 things. The Vortex OS and VParse. The OS is multitasking and handles a lot of features. VParse is a stand alone Vertex2 parser. Vertex is vortex's scripting language. Pre 0.7 is QBasic and 0.7 is C++.

Computer Manager is the first OS that takes advantage of the DOS and Linux filesystems. It also makes doing jobs easier for everyone. Once it is complete, it will be made available to everyone!

DynamOS is a dynamic real-time operating system that can handle different quality of service levels.

FreeOS/1 is a Free, Open Source, FreeDOS based Free and Open Source Alternative OS, with open source Microsoft Windows compatibility using HXDOSExtender KernelEx,and ReactOS source code. FreeOS/1 will include new technologies and will be easy to use

Fusion OS is a Open Source Operating System, mainly licensed under the MPL 1.1. Parts of it are licensed upder the GNU GPL or other open source licenses. Fusion OS is based on the ReactOS project, and we contribute any bugs found in ReactOS back to them

JonOS is an open source 16 bit operating system written 100% in assembly.

Micro-80 aims to simulate a Z80 homebrew computer down to the bare metal: 64K RAM, ADM-3A terminal, parallel port, serial port and...3.5" 1.44MB floppy drive?!

An operating system kernel designed with simplicity, readability, and elegance in mind. No longer written from scratch, but built on "the shoulder of giants." Specifics are given in the CREDITS file starting from v0.04

Pascal Operating System, That will translate Freedos to Pascal --OSPine written in Turbo Pascal and NASM. I think now I will make all that useful before I release. Thank for Feedback (^_^)

Perix is a MS-DOS compatible program, capable of running without an underlining OS. It is written in Turbo Pascal and Assembly. All parts of system are distributed under terms of the GNU General Public License v2.

RxDOS is a fast MS-DOS clone that supports very large disk drives, FAT32 volumes, and Windows 95/98 Long Filenames

Tesoro is an open source operating system project fully written in x86 Assembler language. The architecture is partially based on some QNX ideas and some fresh ideas. It combines low level assembler coding (e.g. microkernel with extremely fast task switch

Merge the Solaris downstream version of GRUB legacy GPL source code into GRUB4DOS

open source analogue of IBM OS/2 operating system

A portable BASIC in the style of Microsoft 6502 BASIC (especially the Apple ][+ variant), with influence from GW-BASIC and Atari BASIC among others, with enhanced features, written in C for portability to computers large and small.