The purpose of deployment system is to make sure that every feature is tested, reviewed and accepted by customer. To accomplish this, deployment system should have support for automated testing, code reviewing and issue management. I don't know any single software which would accomplish all of these, so current solution I use consists of multiple different programs.
- Jira with Greenhopper for issue management ( http://www.atlassian.com/software/jira/, http://www.atlassian.com/software/greenhopper/ )
- Hudson for continuous integration and deployment (http://hudson-ci.org/)
- Gerrit for code review (http://code.google.com/p/gerrit/)
- Git for source control management (http://git-scm.com/)