CI-based Wiki?

[eluser]Grahack[/eluser]
URLs:
About urls, hyphens... see this page and this other one.
One of the difficult things is to give the possibility to any language to be written by the wiki engine, and this includes urls. At least one function will do the transformation from real text to url usable text.

DEV:
There are two options to me:
1) use (or integrate to your website) an already existing and solid wiki engine, perhaps with some little hacks or plugins,
2) build a new one from scratch, grabbing ideas only, not code.

With 1) you won't waste time falling into pitfalls, but learn nothing.
With 2) you learn a lot, and can be proud of your (long) work (if it's good).

To me there's no place for an intermediate option, but everyone is free...