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.
Camunda - The Universal Process Orchestrator
Ranorex - Ranorex is a GUI test automation framework for testing of desktop, web-based and mobile applications.
Appian - See how Appian, leading provider of modern low-code and BPM software solutions, has helped transform the businesses of over 3.5 million users worldwide.
TestComplete - TestComplete Desktop, Web, and Mobile helps you create repeatable and accurate automated tests across multiple devices, platforms, and environments easily and quickly.
Joget.org - Open Source Workflow Software, Business Process Management and Low-Code Application Platform.