The MO Cache provides simple and fast caching of the translation MO files using the <a href="https://codex.wordpress.org/Class_Reference/WP_Object_Cache" rel="nofollow ugc">WP Object Cache</a> mechanism. 
This plugin is necessary to be used <a href="https://codex.wordpress.org/Class_Reference/WP_Object_Cache#Persistent_Cache_Plugins" rel="nofollow ugc">persistent caching plugin</a>, otherwise you can not benefit from this plugin.
For localized WordPress, which was newly installed, the loading time of translation files accounts for 70% of the entire processing time. 
You can make this process 3 times faster by just installing this plugin.
<a href="http://m4i.hatenablog.com/entry/2011/12/10/000407" rel="nofollow ugc">Description in Japanese （日本語での紹介記事）</a>
<h4>Features</h4>
<ul>
<li>No configuration</li>
<li>Supports multiple languages</li>
<li>Supports plugin’s translation files caching</li>
<li>Supports WordPress Network/Multisite installation</li>
<li>A simple plugin in less than 100 lines</li>
</ul>

MO Cache

Simple and Perfect solution.

Improving the site performance by caching translation files using the WordPress standard cache mechanism.

Budiony Damyanov

Easy cache takes a real-time snapshot of every Page, Post, Category, Link, etc. These snapshots are then stored (cached) into folder of your choice, so they can be referenced and served to the visitor later, in order to save database processing time that has been slowing your website down.
The Easy cache plugin uses configuration options that you select from the Administration panel. Search for <code>Easy cache</code> in your <code>Settings</code> page. 
Easy cache excludes administrative or WP system login pages from caching (i.e. it works only on public part of your blog). Only NOT logged-in users (which are the most) can benefit from caching mechanism when they visit the public part of your website. Password-protected pages or posts are excluded from caching too.
There is an automatic cache expiration system, which runs through WordPress® behind-the-scene, according to your <code>Cached file expires after</code> setting, also various cache and server load statistics are available for precise tracking of what is going on.
The Easy cache plugin has been tested with various permalink settings, various pagination plugins like <code>WP Pagenavi</code> and <code>WPML WordPress Multilingual Plugin</code>, also with <code>WordPress® Jetpack</code> mobile theme, with variuos custom post types, custom queries, custom pages outside WordPress® installation directory and a number of widely used plugins, however if you experience troubles, post your issue on the plugin’s forum.
Supported languages
<ul>
<li>
English
</li>
<li>
Spanish
</li>
<li>
French
</li>
<li>
Bulgarian
</li>
</ul>

bodi0`s Easy cache

Speed up your blog with Easy Cache, bullet-proof and easy-to-use website caching mechanism for WordPress that just works.

MO Cache vs bodi0`s Easy cache