http://loader.io/ Loader.io is a free load testing service that allows you to stress test your web-apps/apis with thousands of concurrent connections.
https://github.com/excilys/gatling Gatling is a stress tool. Development is currently focusing on HTTP support.
https://github.com/temoto/weighttp weighttp (pronounced weighty) is a lightweight and small benchmarking tool for webservers.
http://engulf-project.org/ Engulf is a scalable and distributed HTTP benchmarker
https://github.com/tsenart/vegeta Vegeta is a versatile HTTP load testing tool built out of need to drill HTTP services with a constant request rate. It can be used both as a command line utility and a library.
https://github.com/rakyll/boom Boom is a tiny program that sends some load to a web application. It's similar to Apache Bench (ab), but with better availability across different platforms and a less troubling installation experience.
https://www.blitz.io/ Load Testing from the Cloud Load testing for websites, web apps, and REST APIs
https://appintime.com/api/v1/doc.html
git subtree push --prefix sinatra heroku master