The Mozilla plugin (Excerpted from the VLC User Guide)
Install
There are at least two ways to install the VLC Mozilla Plugin. One way is to to check the "Install Firefox Plugin" when you install VLC.
If the standard exe installation does not install the mozilla plugin directory then download zip version which includes the required data and continue with the next installation (2nd way of installing of the plugin)
The second way involves several steps:
1. Quit Firefox or Mozilla
2. Copy the two files in VLC_Installation_folder\mozilla (usually C:\Program Files\VideoLAN\VLC\mozilla) to your mozilla plugins directory (Usually C:\Program Files\Mozilla\plugins or C:\Program Files\Mozilla Firefox\plugins).
3. Restart Firefox or Mozilla
If in the browser you open a link to an audio or video URL handled by the VLC plugin, or if a web page has HTML code that embeds audio or video handled by the VLC plugin, then the plugin should start and play the audio/video. Note the plugin (as of version 1.1.9) does not present any user interface — it has no default control panel and no keyboard shortcuts.
To get the list of the media types handled by the VLC plugin, browse to about:plugins. Conflicts will arise if you have more than one plugin installed that supports the same media type.
See the Web plugin documentation to create HTML pages that use JavaScript to control the plugin.
More example code, as well as a working implementation using Javascript, XHTML, and PHP that auto-detects browsers (the code is good, but the stream doesn't work) can be found at http://altair.videolan.org/~dionoea/vlc-plugin-demo/ (broken as of 2011-09-04)