SQA in PHP

Greetings to all.
It happened that at work you need to more deeply use SQA (software quality assurance). Googling, made while conclusions that you can use

1. phpunit as a means of testing code (simpleTest as an alternative, and other frameworks for testing code)
2. Selenium as a tool for testing web interface
3. code review to improve the quality of the code. (he's refactoring)
upd:
4. code coverage by phpunit + xdebug to determine which code is not used
5. trac based bugtracker

and what else can be used to improve the quality of the code? what techniques?
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Thanks for attention