Apache JMeter - Apache JMeter™.
testRigor - Use plain English to build stable and maintainable functional end-to-end tests.
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.
Hey Load Generator - HTTP load generator, ApacheBench (ab) replacement, formerly known as rakyll/boom
locust - An open source load testing tool written in Python.
Functionize - Functionize combines natural language processing, deep-learning ML models and other AI-based technologies to empower your team to build tests faster that don’t break and run at scale in the cloud.