DDoS-Guard is a Russian Internet infrastructure company which provides DDoS protection, content delivery network services, and web hosting services.
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.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Tilda is a web design tool.
VK is a Russian online social media and social networking service.