I am using Mantis (PHP and MysQL) as a bug tracking tool and I would like to extend it in order to document requirements and technical specifications. Ideally, I should be able to link a defect with a requirement.

Is there a way to integrate a Wiki tool (preferably PHP and MySQL based) into Mantis?

EDITED:

• Instructions how to integrate DocuWiki can be found in this article "Integrating DokuWiki with Mantis"
• Instructions how to integrate MediaWiki can be found here (Thanks Ian)
• Instructions how to integrate TWiki can be found here and here

Suggested alternatives to Mantis: (open source bugtrackers with integrated Wiki)

1. TikiWiki (Php)
2. PhpWiki (Php)
3. Trac (Python) (Thanks ax)
4. Redmine (Ruby on Rails) (Thanks Paul)