RWML Stacks set
The RapidWeaver Multi Language Stacks set is a powerful set of stacks featuring the jQuery based RWML System. Base task of the RWML System is to easily turn a single RapidWeaver project file into a Multi Language enabled website.
So you no longer have to create another project file for each Language. It automatically adds the required HTML Lang(uage) attribute to your content. This is meant to assist search engines and browsers.
It's not only for normal content elements as you are used to with most stacks and plugins. You can also use it to turn the Navigation Menu of your website into a Multi Language element and use it to Switch to another Language.
Besides that the RWML System is smart enough to remember the chosen Language of your website visitors. So when they visit your website again it automatically shows the content in their Language.