Bootstrap is a free and open-source front-end framework for designing websites and web applications. It contains HTML and CSS-based design templates for typography, forms, buttons, navigation and other interface components, as well as optional JavaScript extensions.
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.
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript.
Trustpilot is a customer review management platform that helps online businesses to establish a trusted brand and connect with customers by collecting reviews and gathering feedback to improve customer experience, amplify their online presence, increase conversions and sales, and more.
Eventbrite is an event management solution which helps businesses to plan, manage, & grow events through tools such as ticketing, attendee tracking, & marketing.
Google Calendar is an get a button on its browser toolbar that they can easily click to see upcoming events from google calendar, without ever leaving their page. And if they are on sites that have special events encoded, it can click the button to instantly add events to they calendar.