这种播放插件是怎么实现的？
现在有很多电影网站播放的时候都需要先安装他们的播放插件，请问这是怎么实现的。。。

------解决方案--------------------
插件代码中用CODEBASE指定插件下载包即可,当客户端没有安装这个插件时,就会自动到CODEBASE指定地址去下载并安装插件.

示例:
<object id=wmpobj classid= "clsid:6bf52a52-394a-11d3-b153-00c04f79faa6 " height=400 width=528
codebase= "http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#version=5,1,52,701 " standby= "loading microsoft windows media player components... " type= "application/x-oleobject ">
<param name= "url " value= " "> <param name= "animationatstart " value= "true "> <param name= "autostart " value= "false "> <param name= "showcontrols " value= "true "> <param name= "uimode " value= "none ">
</object>
------解决方案--------------------
好多都是activex的吧