AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Apache is a free and open-source cross-platform web server software.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Phusion Passenger is a free web server and application server with support for Ruby, Python and Node.js.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.