cdnjs is a free distributed JS library delivery service.
Cloudflare Workers is a serverless execution environment that allows you to create entirely new applications or augment existing ones without configuring or maintaining infrastructure.
ConvertKit is an email marketing tool built for content creators.
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.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.