The newest generation of internet browsers all support native HTML 5 video playback without the need for third-party plugins like Adobe Flash.
That in itself is great progress, but there are some minor caveats due to differences in the video codec support. There are three video formats used in the different html 5 <video> tag implementations by the browser vendors:
Firefox, Chrome, IE9+, Safari and Opera will use the .mp4 file. Browsers without H.264 support skip to the .webm or .ogv file and play that instead. If loaded in a browser which does not support the <video> tag, a download link for the media file is displayed instead.
Update February 2015: After a site migration to another server, my hosting provider blocks direct http request to any mp4/ogv/webm media files stored on the server. This affected the example files, so I had to instead stream them through a script, meaning the examples had to be updated and video tests on external sites with deep links to the media files in this server have stopped working. I apologize for the inconvenience.
The above example works on desktop/laptop browser platforms. Handheld platforms handles inline video a little differently. iOS and newer versions of Android (4.0+) works pretty much as expected. The browser in older older versions of Android may need some extra help to launch the video:
Note that the above ActiveX example uses the H.264 encoded .mp4 file, which will only work out-of-the-box on Windows 7 and later versions. To support older versions of Windows with IE, you must encode the video file in the .wmv format, for example using Microsoft Expression Encoder 4