2mac.com -- a 100 byte assembler language utility (with source code) to convert DOS/Windows/UNIX text file line endings into the Macintosh variety. Specifically, it changes all 0a (LF = linefeed), 0a0d (LFCR = linefeed + carriage-return) or 0d0a (CRLF = carriage-return + linefeed) codes into plain 0d (CR = carriage-return) codes for use on a Mac. I found countless complex Windows-Mac conversion routines on the web, but nothing that did this quite so simply.
2windos.com -- a similarly tiny utility (with source code) to convert Mac carriage return codes into the DOS & Windows standard CRLF. Usage as above. It would be trivial to make a corresponding 2unix utility too if required.
mailtext -- converts forms posted by mail from websites into readable text, including the conversion of %xx codes into 8-bit (e.g. Japanese) text. Written in VB (in Word97 as a macro), so should be quite portable.
Qwkview.cmd -- a set of routines to display QWK packet information and optionally allow you to delete unwanted incoming messages (e.g. spam). Written in REXX, so it should be usable on a wide variety of systems, although I've only tested it on Japanese OS/2. This can be combined with Vernon Buerg's List and FV utilities, or the OS/2 ports thereof (use LA instead of FV).
Ren-Long.cmd -- an OS/2 utility to rename long filenames to short, using extended attributes (and back again), so that e.g. you can view the files in LIST. Also Ren-Long-Filter.cmd, a filter version. However, it may be simpler to use Info-ZIP on a FAT drive, i.e. ZIP all the long files up on the HPFS drive, then UNZIP them onto the FAT drive. The long filenames are preserved in the extended attribute. One problem: if you use non-OS/2 utilities to edit a file with a short filename, the long name EA will be lost (so you'd best keep a record of the original filename somewhere -- e.g. by patching my utility).
screen-on.cmd -- a 3-line REXX utility to switch the screen display back on if it has been "hidden" by using ANSI codes to make text black on black, etc.
erl.bat -- batch file subroutine, to check Errorlevel and store it to a variable (or display it etc.)
No1a.com -- a 50 byte assembler language routine from 1994 (with source code) to filter out Ctrl-Z codes from files (e.g. to allow editing in XYWrite).
Btcharge.bas -- a QBASIC utility from 1994, to calculate the cost of phone calls. The figures are out of date, the logic not ... :-)
Convert.bas -- another QBASIC utility from 1994, to convert various units into others. Add / change as many as you like ...
NewName.bat -- a DOS batch file (+ DEBUG script) to make backup copies of a file with unique time-based names. May need patching depending on what codepage your system uses (i.e. in what format times are displayed).
Usage: from a command line, C:\>2mac <DOS.txt >MAC (change "DOS.txt" and "MAC" as appropriate).