Allows you to blog in multi-language, and users to select which to read. Works on every blog UI elements, not just the post.
The logic behind qTranslate is similar to that of xLanguage - both using HTML tag to differentiate the contents of languages and requires no database modification. qTranslate uses HTML comment tag while xLanguage uses the lang=".." attribute.
The major differences lie within the admin interface, qTranslate provides strong Admin UI integration such that user enters the title, the category name and so on in independent textbox. The post is also to be post to an independent editor. While xLanguage, user enters the data in the same input box. For authoring in language that are very similar (like Cantonese and Written Chinese), and that cross-authoring is common, the method that xLanguage use will reduce much duplication work.
Due to the above restriction, qTranslate supports only one-to-one mapping between authoring and viewable lanugage. while xLanguage does not have this restriction. And hence, xLanguage allows all texts to be presented under one single URL for search engine to crawl with. (Think of SEO)
Feature-wise, xLanguage currently lacks of Pre-domain URL Permalinks mode, as well as automatic MO file download. (Note: MO does work in xLanguage but just have to be downloaded manually). Contribution would certainly help in accelerate these getting done :).
Gengo v2.5.3 is not tested with WordPress 2.7 according to the published plugin info.
In Gengo, each translations is a standalone post, linked to the original post. It enables you to create maps between different content. Think of different language version of Wikipedia, basically Gengo is the same - and it helps you to maintain such link table.
In xLanguage, everything is in the same post. The xLanguage approaches make no structural changes to the WordPress itself, and hence should be easier maintain. No extra magic in xLanguage is needed to keep the commenting, searching, popularity counter works.
This is actually the plugin that inspired me to build the xLanguage. The Language Switcher and the xLanguage is working in a very similar way -- Both enable multilingual post by tagging the it. The Language Switcher uses square bracket instead of HTML tag, but have no assisting tools when composing the post. The language code is limited to the length of 2, and offer no fallbacking and overlapping possibility. The permalink url tag must be placed at the end.
Same as xLanguage, it allows user to enable multilingual functionality on single line content like tag, title and such.
Almost the same as Language Switcher, both functionality and working principle. However, jLanguage v1.4 does not have widget for user to select their favorite language. In addition, It currently offer almost no customization, plus it does not work for single line content. The language selection could not affect the MO file selection.
It enables the language tagging by using square brakets instead of standard tag, similar to that of Language Switcher.
Please be aware that Multilingual post v0.2 does not belong to this category at all. It does not enable poster to publish mixed language in a post. The user also cannot selectively view the post in a particular language.
It only does insert the lang=".." tag at the HEAD such that browser can render the page better. xLanguage also does this.
Bunny's Language Linker's way to enable multilanguage blog is minimal and simple, yet the integration is very loose. It works like Gengo, the pros and cons compare to xLanguage is very similar.
Basic Bilingual v0.31 allows you to insert a summaries in a different language. It is yet another very simple plugin.