These are detailed WikiChat installation instructions.
I'm sure most people won't need them, but it can help when things aren't working and you need to figure out where you might have gone wrong.
Step 1: prepare to install phpfreechat
Download phpfreechat from - here
These are the exact shell commands I used. You can omit the 'sudo' part of the command if you don't have root access to your server.
>:/www/wikichat.org/html$ sudo cp ~/downloads/phpfreechat-1.2-setup.php .
>:/www/wikichat.org/html$ cd ..
>:/www/wikichat.org$ sudo chmod go+w html
Step 2: install phpfreechat
Browse to http://example.com/phpfreechat-1.2-setup.php and install phpfreechat by following the installer steps.
I installed into the directory /www/wikichat.org/html/phpfreechat
note: installation will fail if you are enforcing https for all interaction with your website. In this case, you'll need to allow http to complete installation.
Step 3: remove unneeded files and restore security
>:/www/wikichat.org/html$ sudo rm phpfreechat-1.2-setup.php
>:/www/wikichat.org$ sudo chmod go-w html
Step 4: copy WikiChat.php to the extension directory
>:/www/wikichat.org$ cd html/extensions directory
>:/www/wikichat.org/html/extensions$ sudo nano WikiChat.php
I copy and pasted the source code into the file. Nano is just a text editor.
Step 5: modify the configuration options in WikiChat.php
Modify the directory path at the top of WikiChat.php to point to your PhpFreeChat installation directory:-
$wgPFC_Directory = "phpfreechat";
Step 6: modify LocalSettings.php to load WikiChat
>:/www/wikichat.org/html/extensions$ cd ..
>:/www/wikichat.org/html$ sudo nano LocalSettings.php
Added the following line to the bottom of LocalSettings.php
include( "$IP/extensions/WikiChat.php" );
Browse to the Main Page and voila! the chat tab appears.