Packagist is the main Composer repository. It aggregates public PHP packages installable with Composer.
MyZend Core is a group of required classes for MyZend pacakges.
MyZend Email is a ZF2 module to manage the process of sending emails with templates. You could also realy on MailJet/Gmail smtp.
MyZend Geolocation handles Google Maps API to resolve addresses.
Zend Framework 2 module which uses the Steve (mrclay) Clay's Minify library for styles and scripts minification.