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Welcome to FreeDOS

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FreeDOS is an open source DOS-compatible operating system that you can use to play classic DOS games, run legacy business software, or develop embedded systems. Any program that works on MS-DOS should also run on FreeDOS.
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You can play your favorite DOS games on FreeDOS. And there are a lot of great classic games to play: Wolfenstein 3D, Doom, Commander Keen, Rise of the Triad, Jill of the Jungle, Duke Nukem, and many others!
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Need to recover data from an old business program? Or maybe you need to run a report from your old finance system? Just install your legacy software under FreeDOS, and you’ll be good to go!
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Many embedded systems run on DOS, although modern systems may instead run on Linux. If you support an older embedded system, you might be running DOS. And FreeDOS can fit in very well.

FreeDOS is open source software! It doesn’t cost anything to download and use FreeDOS. You can also share FreeDOS for others to enjoy! And you can view and edit our source code, because all FreeDOS programs are distributed under the GNU General Public License or a similar open source software license.

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What’s New

Check out our YouTube channel

We have a YouTube channel to demonstrate FreeDOS and to show off cool DOS programs that you can run on FreeDOS. I usually upload new videos every week - although I haven't posted in a few weeks because of other commitments that are completely sucking my time. New videos should be coming soon. You can also subscribe to the YouTube channel, and you'll get updates when new videos get posted.

Here are some FreeDOS videos that you might like to watch: + Demonstration of the PsychDOS "desktop" running on FreeDOS. This is a completely text-mode "desktop" for DOS, with a bunch of bundled applications + Using GNU CHCP to change the DOS font + Playing the DOS game "Acronia", a 2D sidescroller shooter + Playing "Little Willy", a 2D platformer.

And I sometimes post programming videos. This is sort of an extension of the "Writing FreeDOS Programs in C" video series and ebook from last summer, to teach an introduction to C programming. These are usually very simple programs, good for learning C: + Writing a program to generate characters by ASCII code + Writing a random number generator program + Writing a simple chess board user interface + Writing an "Extended ASCII" table demonstration.

SmallerC compiler for DOS

Smaller C is a simple and small single-pass C compiler, currently supporting most of the C language common between C89/ANSI C and C99 (minus some C89 and plus some C99 features). Currently it generates 16-bit and 32-bit 80386+ assembly code for NASM that can then be assembled and linked into DOS, Windows, Linux and Mac OS X programs. The developer recently released a new version. This release includes: + DOS binaries (regular and DPMI) + CWSDPMI r5 for the DOS DPMI binaries + include and library files + test programs. This release also includes the source code, under the BSD 2-clause license. You can find it on the SmallerC GitHub under the SmallerC releases. We've also mirrored this on the FreeDOS files archive at Ibiblio, under /files/devel/c/smaller-c.

DOjS version 1.6.0

DOjS is a Javascript programming canvas for DOS, and SuperIlu released a new version of DOjS. New features in this release include: + Added JPEG loading through jpeg module + Made JSLOG.txt optional and the filename can be changed as well + Added basic GIF animations loading/rendering through gifanim module + Improved CTRL-DEL, CTRL-BS handling with whitespaces + Added different blend modes which are selected through TransparencyEnabled() + Added QR-Code generator + Fixed/added some examples. This version also includes a FreeDOS distribution ZIP. You can find the new release at DOjS GitHub. We have also mirrored it on the FreeDOS Files Archive at Ibiblio, under /devel/js/dojs

PGME: Program Manager Eternity for DOS

Program Manager Eternity is an application for launching applications in DOS. Mainly, It is for the still very active FreeDOS platform. It works great in other versions of DOS as well. It is built on top of the newly created QuickCrt object-oriented framework for Turbo Pascal 7.0. Available under the GNU GPL. You can download the latest version that uses an installer at PGME's website or you can fetch a packaged version from PGME downloads. We've also mirrored a copy of the installer at the FreeDOS Files Archive on Ibiblio, under /util/menu/pgme

lDebug 2.1 Release 3

lDebug is a 86-DOS debugger similar to the MS-DOS Debug tool. It is free/libre and builds from source using a toolchain including NASM and a C compiler. New features in this version include: * Interrupt 8 hook (Timer) documented and made opt-in * Interrupt 2Dh hook (AMIS, the Alternate Multiplex Interrupt Specification) is opt-in * Tries to unhook interrupt handlers properly if reachable * Expression evaluator additions * Control-C handling improved * Several bug fixes. More details at the lDebug website. Download the new version from lDebug files. We've also mirrored this release on the FreeDOS Files Archive at Ibiblio, under dos/debug/ldebug

Happy 40th anniversary to DOS!

40 years ago today (August 12, 1981) IBM released the IBM Personal Computer 5150. This was the first IBM “PC” and became the basis for all PCs today. (There were other “personal computers” before this, such as the ever-popular Apple II or Commodore personal computers. “Personal Computer” was what you called a computer that would fit on a desk and you could take home with you. It was a personal computer.) And most importantly: IBM released PC DOS 1.0 with the IBM PC, so today also marks the 40th anniversary of the DOS operating system!

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See also: FreeDOS in the news | FreeDOS History