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.
SnapWidget is a set of interactive Instagram, Twitter and 500px widgets.
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.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.