Packagist is the main Composer repository. It aggregates public PHP packages installable with Composer.
Autowiring bundle for Symfony2
Doctrine 2 ORM and Migrations addon for Nette Framework
Mockista is library for mocking, which I've written, because I find mocking in PHPUnit awful.
Nette skeleton with Adminer Editor, Composer, PhpUnit, WebLoader and Less support
Tool for loading or deploying CSS and JS files into web pages