Yes, it's another operating system emulator and this time it's a DOS emulator for the DS. Created as a NEO Compo 2008 entry by wolped, DS-DOS is an MS-DOS clone that serves as a file browser for the DS. Like the operating system that it was based on, DS-DOS will let users view, copy, move, delete and rename files with the appropriate DOS commands, as enumerated below:

date displays the date
time displays the time
cls clears the screen
help displays help
ver displays DS-DOS version
del allows deleting of files copy allows copying of files
move allows moving of files
ren allows renaming of files
dir displays a list of files and directories in current directory
cd change the current directory
lock locks the filesystem, preventing use of del/copy/move/ren
ulok unlocks the filesystem allowing use of del/copy/move/ren

DS-DOS can also boot .nds files, which can be done by typing the filename. If the .nds file is placed in a folder, you need to type in the entire path (foldermyndsfile.nds) unless it's placed in the current active folder. There's a caveat, however: commands longer than five characters has the tendency to "break" certain commands. When this happens, simply restart DS-DOS.

To make use of this application, simply download the application from the link below. Make sure to check out the readme before installation. Enjoy!