Jemm386 and JemmEx are socalled EMMs ( Expanded Memory Managers ) or, more exactly, V86 monitors.

DOS Disk Editor, handles all types of FAT file systems ( including exFAT )

Masm compatible assembler

Home of the HX DOS Extender and its included DPMI-host HDPMI.

Text Editor

displays contents of OMF object modules

Sound Blaster emulation for DOS

PL0 debugger for Jemm

Debug and DebugX (short: Debug/X) are extended versions of MS DEBUG

Utilities for bare metal access to the High Definition Audio controller in DOS

Ring 0 debugger for HDPMI, Jemm and Win31/9X VMM

A few small tools to display PCI info in DOS

Some tools to test and display APIC status in DOS

Simple DOS PCM Player for SoundBlaster 16

Windows Explorer application written in assembly

Tools to play with XMS functions, useful to test XMMs.

Variant of Dos64stub, running binary in compatibility mode

small stub that allows to run "bare" 64-bit PE binaries in DOS

DOS32pae is a "micro" (or perhaps "nano") DOS extender using PAE paging

DOS extended memory (XMS) server

MS-DOS 7.1 FAT32 Bootsector for GPT-partitioned disks

Harddisk check utility

play audio CDs in DOS

AHCI CD/DVD driver for DOS ( real-mode only )

eXtended Memory Manager (XMM) that can manage memory beyond the 4 GB barrier, up to 1 terabyte.

A set of DPMI debuggers for DOS and 16-bit Windows

tool to convert C header files to assembly include files (Masm style)

simple Ultra-DMA DOS driver for "vintage" PCs

The Open Watcom Debugger, with a few bug fixes and trap files for HX. May debug real-mode and protected-mode programs.