ConTEXT
is a freeware text editor.

Using
free ConTEXT customization files for Zillions that we have defined,
scripts will be highlighted according to the ZRF syntax. ZSG files
will also be highlighted.
To
install the customization file into your installed copy
of ConTEXT, do the following:
Hitting
F1 while editing a ZRF file in ConTEXT will bring up the Zillions
Language Reference. This will work automatically if Zillions of
Games is installed to the location
C:\Program
Files\Zillions Development\Zillions of Games
If
Zillions is installed in a different directory you can change
the line beginning with "HelpFile" in ConTEXT\Highlighters\Zillions
ZRF.chl to point to a different location.
Syntax
colors can be customized to suit yourself by modifying ConTEXT\Highlighters\Zillions
ZRF.chl, near the end. Highlight categories include reserved
keywords, preprocessor commands, operators & control, numbers,
comments, quotations, and symbols (parentheses).
ConTEXT
has brace matching features that are very useful for editing
rules files. If the text cursor is positioned directly before
a parenthesis symbol -- '(' or ')' -- then: