Another ShortestWikiContest contender, heavily influenced by SigWik. Written to prove that also PHP can be as short and unreadable as Perl.
 
289 chars of PHP and Shell on 4 lines.

'''Features'''

* Auto WikiWord and URL linking
* OneClick edits
* BackLinks
* Infinite formatting options via WYSIWYG editor ;-)

'''Quick instructions'''

	0. Save the code e.g. as wiphiki.php
	0. chmod the directory 0777
	0. Start the built-in PHP server
	0. Navigate to localhost:8000/HomePage to get started.

'''Code'''

 <?$p=$_SERVER[PHP_SELF];$e=htmlentities($_GET[t]);if($e)`echo "$e">.$p`
 &header("Location:$p");$n=`cat .$p`;echo preg_replace('~htt\S+|([A-Z]\w+){2,}~'
 ,'<a href=$0>$0</a>',`ls -t|head`."<hr><h1>$p</h1><pre>$n"),"<form action=.$p>
 <input type=submit>\n<textarea name=t cols=80 rows=16>$n";
''' Command to start the PHP built-in webserver'''
 $ php -d error_reporting=0 -d short_open_tag=On -S localhost:8000 wiphiki.php

'''License'''

WiPhiki is licensed under the terms and conditions of the MIT License - http://opensource.org/licenses/mit-license

The author of the original WiPhiki code is Smasty (http://smasty.net).
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CategoryWikiImplementation