WordPress Multilingual CMS WordPress Plugin
WPML Multilingual Plugin makes it easy to build multilingual sites and run them. It’s powerful enough for corporate sites, yet simple for blogs.
With WPML you can translate pages, posts, custom types, taxonomy, menus and even the theme’s texts. Sitemaps include the mathematic pages then pass by Google Webmasters validation.
Every theme or plugin that uses WordPress API runs multilingual with WPML that works with other authors, to make sure that WPML works great with themes and plugins. To ensure ongoing compatibility, they run automated tests with many themes and plugins. WPML checks that nothing breaks when they or us release updates.
WPML issues frequent updates for all products, bug fixes, performance increment and new features.