This is really neat! I was able to get the map loader working in Linux after passing a couple bumps:
1. The filenames in Linux are case sensitive, so sprparser.js and actparser.js (as referred in both html) should be SprParser.js and ActParser.js or they will not be found.
2. Some data files are going to use whatever case they want (BLACK.BMP won't find black.bmp). There isn't really anything that can be done in ragnarok-js to "fix" this AFAIK, but in Apache you can get around it by adding the following to httpd.conf:
<Directory /path/to/ragnarok/data>
CheckSpelling On
</Directory>
After doing that I'm walking around Payon.
As for Ragnarok.html, it seems to have a problem loading include/CustomControl.js, which actually doesn't exist in the folder. The login window still comes up though.