Software

BTTR Software
A hobbyist project that provides various open source programs for 80x86-based computers running DOS-compatible operating systems.
http://www.bttr-software.de/

CuteMouse
An open source mouse driver for DOS. It's completely written in assembly for speed and small memory footprint. (Included with FreeDOS; works with others.)
http://cutemouse.sourceforge.net

DOG
A replacement for COMMAND.COM designed to make DOS faster and easier to use.
http://dog.sourceforge.net/

DOS Driver Page
Collection of drivers and utility software to help with running DOS and DOS applications on modern hardware. Includes several sound card and video drivers.
http://www.dosdriver.de/

DOS: The Ghost in the Machine
DOS utilities, graphics, other program; tutorials, reviews, personal recommendations; 2,150+ external links.
http://www.devedia.com/dosghost/

DWin
An Open Source GUI and multitasking system for DOS. Will run on 8086 and takes up very little memory.
http://dwin.sourceforge.net/

FileC
Filename completion for DOS, Windows 95/98/Me. At the command line prompt, type the first few letters of a filename, then hit Tab; FileC fills in the rest of the name.
http://www.morearty.com/filec/

Flashback to Command Prompt
Links to batch files and utililies to take advantage of 4DOS and Take Command.
http://www.gci275.com/websites.shtml

Free Software for DOS
Reviews, descriptions, and download links for a number of DOS utilities and applications.
http://home.att.net/~short.stop/freesoft/

HexEd
Small hexadecimal editor with turbo vision style interface, which is consistent on all platforms. DOS version listed under the "old" downloads section.
http://www.von-bassewitz.de/uz/hexed/

Interesting DOS programs
A collection of links to mostly freeware DOS programs. Includes sound, graphics, screen savers, utilities, programming tools, and DOS alternatives.
http://www.opus.co.tt/dave/index.htm

ISAPNPTOOLS
A set of programs that allow ISA Plug-And-Play devices to be configured on a DOS (and Linux) machine. Suitable for all systems which contain ISA bus Plug-and-Play cards, whether or not they include a PnP BIOS.
http://www.roestock.demon.co.uk/isapnptools/

JHB: My Programs
DOS programs written by J.H. Bass: ASCII reference table, Browser to search for and uncompress Zip files, electronic calendar, electronic piano, math tutor, games: Hangman, Ludo, Rescue, Five in a Row.
http://pages.intnet.mu/jhbpage/My_Programs/myprograms.htm

LFNSORT
A utility to sort Windows' long filenames on a disk.
http://www8.pair.com/dmurdoch/programs/lfnsort.htm

Nansi and NNansi
Enhanced versions of ANSI.SYS. Purported to be faster than ANSI.SYS and includes extra features.
http://alumnus.caltech.edu/~dank/nansi/

NukeSoft Utilities
Contains a basic screen saver, utilities to record the time the system has been running, a program to determine if Windows is running, a calculator, a utility to disable the PC speaker, and other utilities.
http://www.nukesoft.co.uk/nukesoft/

The PCOS Project
Presents this open source project whose goal is to release a shell (command.com replacement) for any flavor of DOS.
http://www.geocities.com/mercury0x000D/

Pysmatic
Contains a number of DOS utilities including improved directory listers, directory changers, and several other.
http://www.pysmatic.com/

Seal
A DOS GUI similar to GEM, OS/2, and Windows. Designed for DOS programmers and users alike. If you do much programming for DOS, this GUI makes it easier for you.
http://sourceforge.net/projects/sealsystem/

UCP/OS Operating Environment
A command.com replacement for DOS.
http://www.geocities.com/ucp_os/