theode

Did you ever struggle with more than one language on a WordPress blog? 
In a world of globalization those struggles reach me very often.
This plugin has the ability to store language codes the in post meta data to have articles with different languages on the same page. This might be interesting for blogs who only need sometimes a different language.
One of those is the following case: 
The boss is writing articles in english but its a german company and needs some articles in german too. 
But the second language articles are unique and not only translations.
You maybe think that would be quite simple using WPML. But what are you doing if you need both languages on the start page? 
For this special case, we wrote a plugin, which is able to show all languages on the home page and manipulates the query if some language is chosen. 
It also makes a difference in terms of SEO as it changes the line
<html xmlns=”http://www.w3.org/1999/xhtml” dir=”ltr” lang=”en-EN”>
according to your language.
For a real working experience you can use it in combination with the <a href="https://wordpress.org/extend/plugins/no-function-language-widget/" title="no function language widget" rel="ugc">no function language widget</a>.

Language Field

If you don't need a full multilingual plugin, but have single articles in a different language.

Oleg Butuzov

For WP 2.3 – 2.5 you should user 1.3.* version
WP_Multilingual is extension that brings WordPress multilingual support. With it’s help you can publish more that in one language at a time. Its easy, cheap and simple way to use multilingual advantages of blogging.
With this plugin you can manage your Posts/Pages/Categories/Blogroll Links/Tags in multilingual mode.
Plugin also allow you to localize theme relate to Selected language, and localize Wp-admin in your language. 
Plugin Localized in
<ul>
<li>Russian</li>
<li>Ukrainian</li>
<li>English</li>
<li>Franch</li>
<li>Italian</li>
<li>Greek</li>
<li>Spanish</li>
<li>Czech</li>
<li>Catalan</li>
<li>Herbew</li>
<li>Deutsch</li>
<li>Dutch (Holland or Netherlands)</li>
<li>Arabian</li>
<li>Polish</li>
</ul>

WP_Multilingual

WP_Multilingual is extension that brings WordPress multilingual support. With it's help you can publish more that in one language at a time.

Language Field vs WP_Multilingual