Apache is a free and open-source cross-platform web server software.
Joomla is a free and open-source content management system for publishing web content.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.