Erunafailaro

The plugin adds a meta-tag to the html-header-part of your blog. This meta-tag contains keywords that describe the contents of the html-page. Adding this kind of meta-tag is one part of the job of optimizing your blog for search engines. To learn more about search engine optimization, I recommend reading and understanding these articles:
<ul>
<li><a href="http://www.geek-notes.com/wordpress/25/optimize-wordpress-for-search-engines" title="About SEO at geek-notes.com" rel="nofollow ugc">about SEO at geek-notes</a></li>
<li><a href="http://www.devlounge.net/articles/plugins-for-a-search-engine-friendly-wordpress-blog" title="About SEO at devlounge.net" rel="nofollow ugc">about SEO at devlounge</a></li>
</ul>
<h3>Plugin Homepage</h3>
The complete documentation is located at my <a href="http://www.weinschenker.name/wptags-4-metakeywords/" title="Plugin-homepage" rel="nofollow ugc">website</a>

WPtags 4 MetaKeywords

This is a tiny, lightweight plugin I wrote to use the new native tagging from WordPress 2.3+ to automatically create a meta-keyword-tag for my blog.

Philipp Speck

This plugin will make it possible to use tags as <code>meta keywords</code>. Under <code>Pages</code> you will find a new meta box called <code>Keywords</code>. 
By activation the plugin registrates a separate taxonomy which is independent from post tags. 
Today’s search engines don’t use <code>meta keywords</code> as a criteria at all, but who knows for what they will be good in future 😉 
For me tagging is necessary to bring pages in relation and gives me the possibility to save my tags redundant in the database.
Features
<ul>
<li>Use post tags as <code>meta keywords</code></li>
<li>Registrates own <code>taxnomy</code> for pages</li>
<li>No coding needed</li>
<li>Language support</li>
</ul>
Related Links
<ul>
<li><a href="http://www.typomedia.org/wordpress/plugins/wordpress-meta-keywords/" title="Homepage of WordPress Meta Keywords" rel="nofollow ugc">Homepage</a></li>
<li><a href="https://wordpress.org/extend/plugins/wordpress-meta-keywords/changelog/" title="Changelog for WordPress Meta Keywords" rel="ugc">Changelog</a></li>
<li><a href="https://wordpress.org/extend/plugins/wordpress-meta-keywords/faq/" title="FAQ for WordPress Meta Keywords" rel="ugc">Questions</a></li>
</ul>
Localization
<ul>
<li>German translation by <a href="http://www.destio.de/" title="Designstudio, Philipp Speck" rel="nofollow ugc">Designstudio, Philipp Speck</a></li>
<li>Slovak translation by Branco Radenovich</li>
</ul>
Note: 
Before installing or upgrading new plugins, please backup your database first!

WordPress Meta Keywords

This plugin gives you the ability to set Meta Keywords in WordPress. Under pages it will registrate a separate taxonomy for keywords.

WPtags 4 MetaKeywords vs WordPress Meta Keywords