What is an open source continuous delivery tool that can be used for a strong continuous delivery pipeline?

Continuous delivery lets development teams automate the process that moves software through the software development lifecycle, and it can provide many benefits when provisioning an integrated toolbox, including the following: -Reduce time to deployment through continuous testing and development -Decrease the costs associated with traditional software development -Scale software development based on project size -Deploy code automatically into each phase of the development cycle A continuous delivery tool enables you to use open source tools to build, deploy, and manage your applications. By integrating sets of tools, you can create repeatable and manageable tasks, not only for your development team but also your operations team. Open source continuous delivery tools you can use for a strong continuous delivery pipeline include: Jenkins, Concourse CI, Spinnaker, Travis CI, GoCD and GitLab CI