Comment 175 for bug 25830

João,

the MIME-type is set by the webserver, not the browser. So it's the webserver
that chooses text/plain for a *.c file. Apache uses the file-extension for it,
it doesn't look in the contents.

Note that Gecko gives priority to the HTTP-header 'Content-Type', not to a
META-tag. So your webpage can't override it inside the page (example 2), unless
there's a way to specify the header (user the header-function in PHP for
example, but that has to be done before the first line is printed).