Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Loader.io - Loader.io is a simple cloud-based load testing service
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
WebLOAD - WebLOAD - The most flexible and cost effective software for enterprise load, stress and performance testing, integrated with DevOps processes. Click for details
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
StresStimulus - Load testing tool for websites and mobile that works with hard-to-test applications.