Selenium provides support for the automation of web browsers. It provides extensions to emulate user interaction with browsers, a distribution server for scaling browser allocation, and the infrastructure for implementations of the W3C WebDriver specification.

Selenium automates browsers. That's it!

Selenide = concise API for Selenium WebDriver

This is selenese script interpreter implemented by Java. It supports test-case and test-suite which are Selenium IDE's native format.

Taxi Toolkit

A web application to provide test pages for running automated tests.