How to install MediaWiki on a subdomain

Here is how to set up MediaWiki on a subdomain and use pretty/short URLs. This was tested on July 1, 2010 with MediaWiki 1.15.4, PHP 5.2.8, MySQL 5.0.90 and Apache 2.2.11. This assumes you are in a shared hosting situation, and do not have root access and cannot edit the Apache configuration files directly. Your …