The Gengo plugin provides a number of template functions which are very similar to those in WordPress:

the_summaries()
Outputs a div with a javascript switcher of all of the summaries for this post, or nothing.
the_translations()
Outputs a list of translations for this post, or “No Translations”.
the_translations_comments()
Outputs a list of links to the comments sections of translations for this post. Use in comments.php.
the_language()
Outputs or returns the language for a page where only one language is being used. Outputs by default. To return the language as a string, call the_language(true).
gengo_list_languages()
Outputs a formatted lists of languages defined for this blog. Surround the call to this function with <ul> tags.
gengo_list_pages()
Replaces wp_list_pages and will output a list of pages that are for the current language only. It is called in exactly the same way and you can use all the same arguments as before.
gengo_list_cats()
Replaces wp_list_cats and will output a list of categories with correct post numbers for each language. It is called in exactly the same way and you can use all the same arguments as before.
gengo_synblock()
Use this to output or return blocks of translated text that will vary based on the page’s language.
the_language_code()
Outputs or returns the current language code. Outputs by default. To return the code as a string, call the_language_code(true).
the_language_locale()
Outputs or returns the current language locale. Outputs by default. To return the locale as a string, call the_language_locale(true).
gengo_trackback_url()
Replaces trackback_url().
gengo_next_posts_link() / gengo_previous_posts_link()
Replaces next_posts_link() and previous_posts_link().
gengo_link_pages()
Replaces link_pages().

More on Gengo

If you want to help out and write/translate tutorials for Gengo:

Other Languages: