Apache is a free and open-source cross-platform web server software.
Blitz provides intelligent static page caching for creating lightning-fast sites with Craft CMS.
cdnjs is a free distributed JS library delivery service.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Lightbox is small javascript library used to overlay images on top of the current page.
Open Graph is a protocol that is used to integrate any web page into the social graph.