Sergey Biryukov

Converts gettext binary message catalogs to an array of strings. Allows to save some amount of RAM on a shared hosting server. 
Works with plugin and theme textdomains as well as with the default.
Thanks to AlexPTS for the idea.

Pure PHP Localization

Лучший и, скорее всего, единственный рабочий плагин. Спасибо, Сергей

Пожалуй, лучший плагин для кеширования переводов

Converts gettext binary message catalogs to an array of strings.

Creates a separate tiny .mo file to use on a site front-end. Allows to save some amount of RAM on a shared hosting server.
Thanks to MAX for the original non-plugin solution and to AlexPTS for the idea.

WPLANG Lite

Creates a separate tiny .mo file to use on a site front-end.

Pure PHP Localization vs WPLANG Lite