SaltwaterC

XVE (XVE Various Embed) is a simple yet powerful way to add media content to your WordPress blog. It is a drop-in replacement for my old XHTML Video Embed plug-in, while it aims to continue the original support.
The plug-in is self documented, so there’s the point where you may want to start. The help is integrated into the WordPress help system. If you’re looking for it, it’s into the above menu, the ‘Help’ item. For some of you, this isn’t so obvious as the Help system is kinda new.
New features and support requests are honored better if you open a <a href="https://github.com/SaltwaterC/XVE-Various-Embed" title="GitHub" rel="nofollow ugc">ticket on GitHub</a> where this plug-in is actually hosted.
Supported video services: youtube.com (youtu.be URLs as well), metacafe.com, dailymotion.com, revver.com, spike.com, vimeo.com, livestream.com, capped.tv, trilulilu.ro, 220.ro, collegehumor.com, myvideo.de, snotr.com, gametrailers.com, blip.tv
Supported audio services: trilulilu.ro, 220.ro
Supported image services: trilulilu.ro
It also supports generic SWF / FLV (MP4) embedding.
For the FLV (MP4) embedding, there are three provided players: Flowplayer, FLV Player, and JW Player. You may change them on the fly without the need to change the embed code.

XVE Various Embed

XVE (XVE Various Embed) is a simple yet powerful way to add media content to your WordPress blog.

Nikoya

Check the doctype validity using W3c validator (html , xhtml , … ) when creating or updating page / post / custom post type and show the result in backend 
It show the result in back-end in sortable column, a link is add to the w3c for all file to help you to correct html error.
Very easy to see if a post / page is valid or not.
This plugin can check the W3C validity of your page / post or custom post type even if the site is not accessible from the Internet (if you work on local system for example)

(x)html easy validator

Check the doctype validity using W3c validator (html , xhtml , ... ) when creating or updating  page / post / custom post type and show the result in  …

XVE Various Embed vs (x)html easy validator