Apache is a free and open-source cross-platform web server software.
Debian is a Linux software which is a free open-source software.
Gravatar is a service for providing globally unique avatars.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Issuu is a digital discovery and publishing platform.
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.