Sikuli - Sikuli Script
Selenium - Selenium automates browsers. That's it! What you do with that power is entirely up to you. Primarily, it is for automating web applications for testing purposes, but is certainly not limited to just that.
GitLab - Create, review and deploy code together with GitLab open source git repo management software | GitLab
DalekJS - DalekJS is an open source UI testing tool.
UI.Vision - Modern open-source task and test automation tool and Selenium IDE.
Webinject - WebInject is a free tool for automated testing of web applications and web services.