Use the mine type

How to install on your website ?

Include the following code into your website :
<object type="application/ogg" data="http://www.yourwebsite.com/yourvideo.ogg" width="320" height="240">
<param name="src" value="http://www.yourwebsite.com/yourvideo.ogg"/>
alt : <a href="http://www.yourwebsite.com/yourvideo.ogg">yourvideo.ogg></a>
</object>
You can also use the new mine-types of the Xiph Foundation such as .ogv and .oga.
<object type="video/ogg" data="http://www.yourwebsite.com/yourvideo.ogv" width="320" height="240">
<param name="src" value="http://www.yourwebsite.com/yourvideo.ogv"/>
alt : <a href="http://www.yourwebsite.com/yourvideo.ogv">yourvideo.ogv></a>
</object>
For further information about those new mine-types, go and read http://wiki.xiph.org/index.php/MIME_Types_and_File_Extensions