I either didn't know or forgot notepad++ is open source. Nice. I'm still not interested to work on syntax highlight for it now, but maybe in some distant future, now it makes more sense (although there's no linux binary, so I would have to run it with wine).

Kate: I'm not sure about windows, but in linux you put your customization files like syntax highlight or color schemes to folder local to the user, I have it in the comments of the file itself, as it's a bit hidden. I would expect the windows versions of KDE apps to have also configuration stored in some user directory, try to change few options and store the new config, it must be written somewhere. If you will find it, and compare the folder tree against what is used on linux, you will probably find where to put syntax highlight rules too. Or maybe it's even in documentation?