ikiwiki should support utf-8 pages, both input and output. To test, here's a utf-8 smiley:
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Currently ikiwiki is belived to be utf-8 clean itself; it tells perl to use binmode when reading possibly binary files (such as images) and it uses utf-8 compatable regexps etc.
There may be the odd corner where utf-8 still doesn't work; these are being fixed as they're found.
Notes:
- Apache "AddDefaultCharset on" settings will not play well with utf-8 pages. Turn it off.