Apache is a free and open-source cross-platform web server software.
Drupal Multisite enables separate, independent sites to be served from a single codebase.
Drupal is a free and open-source web content management framework.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Mailchimp is a marketing automation platform and email marketing service.
Mautic is a free and open-source marketing automation tool for Content Management, Social Media, Email Marketing, and can be used for the integration of social networks, campaign management, forms, questionnaires, reports, etc.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
Typekit is an online service which offers a subscription library of fonts.
Varnish is a reverse caching proxy.