AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Akismet is a service that filters spam from comments, trackbacks, and contact form messages.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
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.