Ranorex Studio supports test automation on a broad array of platforms, from legacy desktop applications to the latest web and mobile technologies. Ranorex Studio tools help teams automate faster, identify defects, and reduce test maintenance, so that you can focus on delivering quality applications.
Tsung - Tsung is an open-source multi-protocol distributed load testing tool.
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
gatling - A high performance web server. Small! (125k static Linux-x86 binary with HTTP, FTP and SMB support).
TestComplete - TestComplete Desktop, Web, and Mobile helps you create repeatable and accurate automated tests across multiple devices, platforms, and environments easily and quickly.
locust - An open source load testing tool written in Python.
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.