ImageJ macro syntax highlighter is available with IJ_ED and Fiji Scripting Editor. Both are plugins for ImageJ. I have not seen IJ macro syntax highlighter with other available editors around, so I made one for Notepad++, a now famous text editor for Windows. Here is the download link for the configuration file.

http://cmci.embl.de/downloads/npp_syntaxhighlighter

I think it should be great also with Vim. I might prepare one as well later.