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.

scalatestplus-play

Automated driver management and other helper features for Selenium WebDriver in Java

XWiki Platform - UI Tests Framework

Selenide = concise API for Selenium WebDriver

Vaadin TestBench

Jakarta Faces 4.1+ utility library

Serenity Core

Vaadin TestBench shared classes not dependant on any concrete testing framework.

Java library which provides helper methods for invoking the Sauce Labs REST API

LittleProxy is a high performance HTTP proxy written in Java and using the Netty networking framework.