Emacs is a free software (GNU / GPL v2) on mostly platforms.
More informations on the official web site : http://www.gnu.org/software/emacs/.
Ok, this is a basic highlighting for any Scol packages (*.pkg extension). You may modify it ... :)
First, get these lines below :
Or, if you wish, download the file (right click, "Save link as ... ") directly on your pc : 50scol.el.
It's written in (E)Lisp. You can find a lot of tutorials on the web if you want modify my little code.
Twice, you can use this method (it's not imperative !)
Copy this file into /etc/emacs/site-start.d/ (1);
Add this line in your .emacs (2):
(setq auto-mode-alist (cons '(*.pkg' . scol-mode) auto-mode-alist))
Relaunch Emacs. You could read this line :
Loading /etc/emacs/site-start.d/50scol.el (source)...done
Test the highlight. Open any pkg file, the hightlighting should be ok :)
(1) : you should be root to do this.
(2) : by default, this file (.emacs) is in your home directory (/home/your_login) on GNU / Linux system. On MS Windows, it is at the first partition root (c:/).