Gravatar is a service for providing globally unique avatars and was created by Tom Preston-Werner. It is owned by Automattic, having integrated it into their WordPress.com blogging platform.
PHP: Hypertext Preprocessor is a server-side scripting language designed for Web development, but also used as a general-purpose programming language. PHP code may be embedded into HTML code, or it can be used in combination with various web template systems, web content management systems, and web frameworks.
Typekit is an online service which offers a subscription library of high-quality fonts. The fonts may be used directly on websites or synced via Adobe Creative Cloud to applications on the subscriber's computers.
Cloudflare Content Delivery Network (CDN) is a geographically distributed group of servers that ensure fast delivery of Internet content, including HTML pages, JavaScript files, stylesheets, and images.
Plesk is a commercial web hosting and server data center automation software with a control panel developed for Linux and Windows-based retail hosting service providers.
YouTube is a video sharing service where users can watch, like, share, comment and upload their own videos. The video service can be accessed on PCs, laptops, tablets and via mobile phones.