Apache is a free and open-source cross-platform web server software.
Contact Form 7 is an WordPress plugin which can manage multiple contact forms. The form supports Ajax-powered submitting, CAPTCHA, Akismet spam filtering.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Contact Form 7 v5.1 dropped support for reCaptcha v2 along with the [recaptcha] tag December 2018. This plugin brings that functionality back from Contact Form 7 5.0.5 and re-adds the [recaptcha] tag.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
RxJS is a reactive library used to implement reactive programming to deal with async implementation, callbacks, and event-based programs.
Unix is a family of multitasking, multiuser computer operating systems.
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.
WP Fastest Cache is one of a number of plugins for WordPress designed to accelerate the performance of your website.
Yoast SEO is a search engine optimisation plugin for WordPress and other platforms.