Apache is a free and open-source cross-platform web server software.
Flickity is a JavaScript slider library, built by David DeSandro of Metafizzy fame.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
Twenty Eleven is the default WordPress theme for 2011.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.