Try trac. Redmine is a poor copy of Trac. Trac is a wonderful piece of software once you get used to it. Nothing can match the plugin model, reliability and extensibility of it.
Name something else which we can customise, make client facing easily, have AD authentication working against, use for documentation, source tracking, ticket mangement and infrastructure management with an administration effort of 30 minutes a month at average, that costs $0?