AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
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.
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.
Squarespace Commerce is an ecommerce platform designed to facilitate the creation of websites and online stores, with domain registration and web hosting included.
Squarespace provides Software-as-a-Service (SaaS) for website building and hosting, and allows users to use pre-built website templates.
Typekit is an online service which offers a subscription library of fonts.