Thanks! I tried your HTML5 suggestion and installed CKEditor4 in my site. But the next question is: when to add some <audio> tag in the "source" mode, i.e. <audio src="horse.ogg" controls="controls"> LISTEN </audio>, the result after I saved my post is just a word LISTEN. Is it possible to use HTML5 tag in CKEditor4? BTW, my browser is Chrome.