Microsoft 
MS-DOS and Windows 
http://david.tribble.com/programs.html
Caveat: 
Unless otherwise noted, most of these programs were originally written and compiled on 16-bit MS-DOS, and may not work very well when run on 32-bit Windows, especially in the way that they fail to handle long file names. 
bin2bmp.exe 
Converts a binary data file into a BMP image file. 
Some people, to my surprise, have actually found this program useful. 
bmpdump.exe 
Dumps the contents of a BMP bitmap image file in hexadecimal form. 
cat.exe 
Catenates the contents of one or more files, writing to the standard output (a la the Unix 'cat' utility). Similar to the DOS 'type' command, but better. Has several options for converting between different end-of-line conventions. 
chtime.exe (32-bit DOS) 
Modifies the timestamp of one or more files (a la the Unix 'touch' utility). 
detab.exe 
Converts the tabs in a text file into spaces. 
diskuse.exe 
Displays the free and used space on a disk drive. 
ebcdic.exe 
Converts an ASCII file into EBCDIC or visa versa. 
entab.exe 
Tabifies a text file by converting spaces into tabs. 
filldisk.bat (16-bit and 32-bit DOS) 
Documentation: filldisk.html 
Fills a hard drive with many large random data files, effectively erasing all the unused and deleted file blocks on the drive. 
fsplit.exe 
Splits a large file into several smaller files. The smaller files may br recombined using the DOS 'copy' command or my 'cat' utility. 
fstat.exe 
Displays information about files. The information displayed can be tailored using a number of formatting options. 
gifdump.exe 
Dumps the contents of a GIF bitmap image file in hexadecimal form. 
hdump.exe (32-bit DOS) 
Dumps the contents of one or more files in hexadecimal and character form. 
head.exe 
Displays the first few lines of a text file (a la the Unix 'head' utility). 
reboot.com 
Reboots the computer. 
Admittedly, this is not very useful. 
scram.exe 
Documentation: scram.doc 
Encodes or decodes a binary or text file into a text-only format suitable for emailing. Handles different end-of-line conventions for text files. 
snow.exe 
Fills a 320x200 VGA display with 'snow'. 
Admittedly, this is not very useful. 
tcopy.exe 
Copies files to a destination directory if they don't exist or are out of date. Similar to the DOS 'replace' command, but better. Has several options for controlling how the copying takes place. 
tee.exe (32-bit DOS) 
Copies standard input to standard output and to one or more files (a la the Unix 'tee' utility). 
tod.com 
Simple utility that displays the time and date. 
unicode.exe 
Converts an ASCII text file into Unicode or visa versa. Handles big-endian or little-endian encoding. 
uniq.exe 
Removes adjacent duplicate text lines from standard input (a la the Unix 'uniq' utility). 
vdate.exe 
Displays the current date and time. The output can be tailored using a number of formatting options. 
vecho.com 
Simple utility for writing arbitrary characters and escape sequences to standard output (a la the Unix 'echo' utility). Similar to the DOS 'echo' command, but more sophisticated. 
vfind.exe (32-bit DOS) 
Locates file and directory names matching specified wildcarded names and other search criteria. Recognizes long file names if running in a Windows shell. 
what.exe (32-bit DOS) 
Searches for "what" strings embedded within files (similar to the Unix 'what' utility). Such strings are prefixed by the character sequence "@(#)" and typically contain source revision information about the file. Many source code revision control systems, notably SCCS, use these embedded "what" strings to track the source code used to build executables and libraries. 
whence.exe 
Locates the files corresponding to specified commands by searching the current PATH settings. 
wordc.exe 
Simple utility that counts the number of characters, lines, and words in one or more text files.
Microsoft 
MS-DOS and Windows 
http://david.tribble.com/programs.html
Caveat: 
Unless otherwise noted, most of these programs were originally written and compiled on 16-bit MS-DOS, and may not work very well when run on 32-bit Windows, especially in the way that they fail to handle long file names. 
bin2bmp.exe 
Converts a binary data file into a BMP image file. 
Some people, to my surprise, have actually found this program useful. 
bmpdump.exe 
Dumps the contents of a BMP bitmap image file in hexadecimal form. 
cat.exe 
Catenates the contents of one or more files, writing to the standard output (a la the Unix 'cat' utility). Similar to the DOS 'type' command, but better. Has several options for converting between different end-of-line conventions. 
chtime.exe (32-bit DOS) 
Modifies the timestamp of one or more files (a la the Unix 'touch' utility). 
detab.exe 
Converts the tabs in a text file into spaces. 
diskuse.exe 
Displays the free and used space on a disk drive. 
ebcdic.exe 
Converts an ASCII file into EBCDIC or vice versa. 
entab.exe 
Tabifies a text file by converting spaces into tabs. 
filldisk.bat (16-bit and 32-bit DOS) 
Documentation: filldisk.html 
Fills a hard drive with many large random data files, effectively erasing all the unused and deleted file blocks和on the drive. 
fsplit.exe 
Splits a large file into several smaller files. The smaller files may be recombined using the DOS 'copy' command or my 'cat' utility. 
fstat.exe 
Displays information about files. The information displayed can be tailored using a number of formatting options. 
gifdump.exe 
Dumps the contents of a GIF bitmap image file in hexadecimal form. 
hdump.exe (32-bit DOS) 
Dumps the contents of one or more files in hexadecimal and character form. 
head.exe 
Displays the first few lines of a text file (a la the Unix 'head' utility). 
reboot.com 
Reboots the computer. 
Admittedly, this is not very useful. 
scram.exe 
Documentation: scram.doc 
Encodes or decodes a binary or text file into a text-only format suitable for emailing. Handles different end-of-line conventions for text files. 
snow.exe 
Fills a 320x200 VGA display with 'snow'. 
Admittedly, this is not very useful. 
tcopy.exe 
Copies files to a destination directory if they don't exist or are out of date。Similar to the DOS 'replace' command, but better. Has several options for controlling how the copying takes place. 
tee.exe (32-bit DOS) 
Copies standard input to standard output and to one or more files (a la the Unix 'tee' utility). 
tod.com 
Simple utility that displays the time and date. 
unicode.exe 
Converts an ASCII text file into Unicode or vice versa. Handles big-endian or little-endian encoding. 
uniq.exe 
Removes adjacent duplicate text lines from standard input (a la the Unix 'uniq' utility). 
vdate.exe 
Displays the current date and time. The output can be tailored using a number of formatting options. 
vecho.com 
Simple utility for writing arbitrary characters and escape sequences to standard output (a la the Unix 'echo' utility). Similar to the DOS 'echo' command, but more sophisticated. 
vfind.exe (32-bit DOS) 
Locates file and directory names matching specified wildcarded names and other search criteria. Recognizes long file names if running in a Windows shell. 
what.exe (32-bit DOS) 
Searches for "what" strings embedded within files (similar to the Unix 'what' utility). Such strings are prefixed by the character sequence "@(#)" and typically contain source revision information about the file. Many source code revision control systems, notably SCCS, use these embedded "what" strings to track the source code used to build executables and libraries. 
whence.exe 
Locates the files corresponding to specified commands by searching the current PATH settings. 
wordc.exe 
Simple utility that counts the number of characters, lines, and words in one or more text files.