cross-browser standards for <object> tag?

I've been trying to make all of my sites compliant with the latest W3 specs, and am finding difficulty in doing so while still embedding multimedia content. In a nutshell, only IE supports doing this via the <object> tag, while Netscape 6.x and Opera 6.x only support this via the <embed> tag, which has never appeared in any W3 spec.

For instance, on one of my pages with an embedded SMIL presentation (http://www.pushback.com/terror/mines/SMIL.html), I have the code shown at the end of this message. This works, but only on IE, and only if you have installed the Real Player first. I thought the <object> tag was supposed to be cross-platform, and also support automatic installation of plug-ins.

But the HTML 4.01 spec does not provide enough detail to show me (or browser authors, which I presume is why there is a problem) how to write or handle <object> completely. My understanding is that the classids that start with "clsid:" are ActiveX-specific, and may have something embedded in them that indicates where the plugin can be downloaded. Is this true, or not?f

I can find no good examples in the specs on how to format the codebase attribute to enable a multi-platform download location; the only examples I've seen are from years-old ActiveX plug-ins, and these appeared to always be Windows specific. So what then, is the official way to format an <object> to point to a cross-platform plugin, and are there any browsers that support this?


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<object id="video1" type="audio/x-pn-realaudio" classid="clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA" height="240" width="320" standby="Loading Real Media Player components...">

<param name="controls" value="ImageWindow" />

<param name="console" value="Minesweeper" />

<param name="autostart" value="false" />

<param name="src" value="http://www.pushback.com/terror/mines/MineSweeper.ram" />

<p>Please <a href="http://www.pushback.com/terror/mines/MineSweeperModem.ram">click here to view the clip</a>

in the separate Real Player application, once you have installed it:</p>

<!--© Peter K. Sheerin-->

<p>You are probably seeing this message because you don&#8217;t have the Windows Media Player

installed.</p>

<p>To fix this problem, please download the Real Player:

<a href="http://www.real.com/RI/RC.011204realhome_1.rnav.img..RI/realone/index.html?src=011204realhome_1" >

<img src="/images/realone_free_88x31.gif" alt="Get the RealOne audio and video player" width="88" height="31" /></a>

and then reload this page. If you still don&#8217;t see the embedded video, then it is because your browser

doesn&#8217;t support the Web standard for embedded video. Instead, please click on one of the links below to

play the video separately in the Real Player.</p>

</object>