Apache Tomcat is an open-source implementation of the Java Servlet, JavaServer Pages, Java Expression Language and WebSocket technologies.
Google PageSpeed is a family of tools designed to help websites performance optimisations.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
SendPulse is an email marketing platform with additional channels: SMS, web push notifications, Facebook and WhatsApp chatbots.
VK is a Russian online social media and social networking service.