Ralf Brown's Interrupt List
A list of interupts used on the Intel x86 architecture and their meaning with over 9000 linked pages and 350 indexes greatly ease the process of searching. (USA Midwest mirror)

X2FTP Archive
General DOS programming material.

Ralf Brown's Interrupt List
A list of interupts used on the Intel x86 architecture and their meaning with over 9000 linked pages and 350 indexes greatly ease the process of searching. (USA East coast mirror)

UPX
The Ultimate Packer for eXecutables is a portable, extendable, high-performance executable packer for several different executable formats. Freeware.

386SWAT
A Protected Mode Debugger which provides debugging services to real mode, protected mode, virtual 8086 mode programs, DPMI and VCPI clients, and Win 3.1x and Win95/98 programs under any memory manager while occupying only a few kilobytes of low DOS memory.

Mouse Programming in DOS
Information on using interrupt 33h for mouse programming. Includes free C source code.

comp.os.msdos.programmer FAQ
Freqently asked questions about programming for MS-DOS with tested answers.

Programming MS-DOS with Power
Information on most every aspect of DOS programming.