Apache is a free and open-source cross-platform web server software.
Google Sign-In is a secure authentication system that reduces the burden of login for users, by enabling them to sign in with their Google account.
Handlebars is a JavaScript library used to create reusable webpage templates.
Open Graph is a protocol that is used to integrate any web page into the social graph.
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.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.