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.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
Sumo is a plugin offering set of marketing tools to automate a website's growth. These tools help drive extra traffic, engage visitors, increase email subscribers and build community.
Varnish is a reverse caching proxy.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.