AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Contact Form 7 is an WordPress plugin which can manage multiple contact forms. The form supports Ajax-powered submitting, CAPTCHA, Akismet spam filtering.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
SoundCloud widget gives you the ability to upload, manage and share tracks.
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.
WP Engine is a website hosting provider.