Continuous Integration is the practice of merging in small code changes frequently - rather than merging in a large change at the end of a development cycle. The goal is to build healthier software by developing and testing in smaller increments. This is where following tools & services comes in.
Jenkins -> Build great things at any scale. The leading open source automation server, Jenkins provides hundreds of plugins to support building, deploying and automating any project.
CircleCI -> CI/CD platform lets teams build and deliver great software, quickly and at scale, either in the cloud or on a self-hosted server.
TeamCity -> Initially a Continuous Integration server, TeamCity has encompassed all the features you’d expect from a mature Continuous Deployment platform. Today it is the best choice for both that you can make.
GitLab -> A complete DevOps platform. With GitLab, you get a complete CI/CD toolchain in a single application. One interface. One conversation. One permission model. Thousands of features.
Travis CI -> A hosted continuous integration service used to build and test software projects hosted at GitHub and Bitbucket. Travis CI provides various paid plans for private projects, and a free plan for open source.
Drone -> A self-service Continuous Integration platform for busy development teams.
GitHub Actions -> Easy to automate all your software workflows, now with world-class CI/CD. Build, test, and deploy your code right from GitHub.