Apache is a free and open-source cross-platform web server software.
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.
PHP is a general-purpose scripting language used for web development.
Spotify Widgets provide an embeddable view of a track, artist, album, user, playlist, podcast or episode for use within your web project.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.