Apache is a free and open-source cross-platform web server software.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Linkedin Ads is a paid marketing tool that offers access to Linkedin social networks through various sponsored posts and other methods.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
SmtpJS is a free library you can use for sending emails from JavaScript.