HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Joomla is a free and open-source content management system for publishing web content.
Mailchimp is a marketing automation platform and email marketing service.
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.