Structuring "Genodians"

John mentionned that the articles are piling up, burying the older ones and their knowledge down the page..

For the sake of information seekers (and the sake of authors! -- articles writers will feel their contribution is more valuable), there should be a way to retrieve info by looking up a topic, keyword ..etc.

Does a wiki help with that? Or maybe it's just sufficient to tag each article; and then provide a list of tags in an index page, which will act as a mini "table of contents"? And anybody is free (encouraged) to link to any article from any documentation they write of course.