I'm new to Zend Framework 2.0, after reading the documentation I know that we can install Zend via some package managers as Pyrus, Composer. But I don't know which package manager should I choose? Please explain to me some differences between them, thank you for help!
Pyrus is basically PEAR2, and needs the end developer of a package to configure a pyrus distribution channel to make packages public.
Composer is backed by the main packagist.org repository, with the availability of own channels through satis if necessary.
Pyrus is mantained, but has not much activity on its main repository, composer is much more active.
Composer is the most used package manager for PHP currently available. Most ZF2 modules currently support it and don't support Pyrus, so I strongly suggest you to get used to it.
Related: ZF2 + doctrine without composer (an example of how this tool is becoming necessary).