1. Install XiphQT <http://www.xiph.org/quicktime/>
2. Go to <http://people.mozilla.com/%7Eprouget/videos/ogv/demo_worker.ogv>
Safari downloads the file instead of playing it in a media document.
This file is served with a Content-Type of "application/ogg".
There are at least two problems here:
1. WebView::canShowMIMEType returns false for this MIME type, because it does not ask MediaPlayer whether the MIME type is supported.
2. Even if canShowMIMEType did ask MediaPlayer, MediaPlayer would claim not to support application/ogg. QuickTime reports that it supports this MIME type, but QTMovieWin filters out all MIME types that don't start with "audio/" or "video/", so MediaPlayer wrongly reports that QuickTime does not support this MIME type.