You can use the standard HTML lang
attribute:
<span lang="en">Scale</span><span lang="de">Maßstab</span>
And then you can hide and show the matching elements:
function select_language(language) {
$("[lang]").each(function () {
if ($(this).attr("lang") == language)
$(this).show();
else
$(this).hide();
});
}
I use a simple selection:
<select onchange="select_language(this.options[this.selectedIndex].value)">
<option value="en" selected>English</option>
<option value="de">Deutsch</option>
</select>