Since I had to search a bit hard on
this one, you might be interested in HOW TO CHANGE A DEFAULT
APPLICATION that is called when you open a file within your
browser.I just wanted to click on a link, that proofed to be a
mms-video-stream, to open in my favorite video player VLC, instead it ended up
opening in the rosetta-translated ages old windows media player for
mac. That was simply a no go.

“was”

Searching through various preferences in Mac OS and its
applications, even within Firefox as
it is done on Windows…
…I found this entry (already fixed):

kobaans-computer:~ kobaan$
defaults find mms

Found 1 keys in domain ‘com.apple.LaunchServices’: {
LSHandlers = (
{LSHandlerRoleAll = “org.videolan.vlc”; LSHandlerURLScheme = mms;
}

Since modifying plist files can be tricky for some people (not
using developer tools, or being familiar with “vi” and/or
“defaults” class syntax) I found that great application (actually a
preferences panel) called RCDefaultApp, which can be used to change and inspect
almost every file/mime/uri/… handling on Mac OS easily.

Enjoy.
Kobaan.