stumbled upon http://coforum.de one day, discovered the ability of contributing myself weeks later, started http://kooperative.mphase.net for my own purposes and   
extended this now allready quit outdated version of PhpWiki with page-related variables, stylesheet-support, vererbung and some other features. 

* simple Unicode html entities passthrough like Π by 

{{{
$Line = str_replace('&', '&', $Line);

// allow special chars // mk 04.07
$Line = preg_replace("|&(\w{2,6});|", "&\\1;", $Line);
$Line = preg_replace("|&(#\d{3,4});|",  "&\\1;", $Line);

}}}

* http://mk.mphase.net