jupp is a fork of an older, more stable, version of joe (JOE’s Own Editor) with backported fixes and features, as well as lots of own bugfixes and new functionality. JOE was already configurable and came in several flavours (joe, jstar, jpico, jmacs, …) and jupp adds another flavour grown from over a decade of use.

jupp has cleaner code, less bugs, triggers less compiler warnings and is less likely to crash on you. Furthermore, it favours:
• UTF-8 support on non-locale-aware OSses
• tab completion fixes
• improved options menu
• visibled spaces
• with --disable-getpwnam can be linked statically on (e)glibc
• CUA style keybindings in all flavours; -keymap cua in all flavours for which this makes sense, i.e. all except jmacs, jpico
• can be linked with e.g. dietlibc or klibc for rescue systems
• can be linked with µClibc on ARM for use on Android (by XVilka)

Neat tricks:
• The notation “^X”, where X is a commercial at sign, an uppercase letter, square bracket, backslash, a(nother) caret or an underscore, means to press the Ctrl key and hold it down while hitting the second key, then release the Ctrl key again. Most key sequences in jupp use either the ^Xy (or ^X^Y or ^XY) style or the ^[. style – “^[” is Esc
• Help: ^J – navigate with Esc+. and back with Esc+, (there are several pages)
• The last reference card of the online help system contains an ascii(7) table / 8-bit character map
• Search for non-ASCII characters in jupp: ^Q f \ [ ^ tab \ n space - ~ ] return return
• Jump to first occurrence of word “rtn” in the files: jupp -mold 'ffirst,"\\<rtn\\>",rtn,"i",rtn' /etc/joe/*rc
• Remove whitespace from EOL: ^K ]
• Hex Editor: ^O g
• Syntax highlighting: on/off ^O h – set syntax ^O y
• xterm: hold the Shift key pressed while moving to easily select text

There’s also Win32 binaries (based on Cygwin) of the current version, as well as 16-bit MS-DOS® compatible binaries of the older 2.8 series.