I think the answer here is that Netbeans DOES support multiple language, but it will only get it right if there's something hinting at the "inner" language. When I exit PHP with ?>
NetBeans tends to format what comes before the next <?php
as HTML automatically. Not sure if that is working for you. Maybe you were trying to get highlighting in a string like $output = "<some><html";
. I think you can imagine why that second one wouldn't work.
For JS, for example, it seems to look for the <script type="text/javascript">
, and stuff inside gets the JS highlighting even if the file type is PHP.
This other question has a great solution for "tricking" Netbeans into rendering your JS output by PHP into being formatted, even when your code doesn't have a <script type="text/javascript">
tag.