With PmWiki there is a really very powerful version with translations, templating, various ready-made layouts (which also don't just look ugly in wiki primitive styling) and mountains of options. And funnily enough, it's much easier to understand than many high-end CMS systems. I like it very much, even though the thing is written in PHP - a language that I simply find disgusting. Well, as long as good systems come out of it, that's fine with me.