** Lots of free-for-open-source services: [https://travis-ci.com/ TravisCI], [https://circleci.com/ CircleCI], [https://www.appveyor.com/ AppVeyor], [https://github.com/bleenco/abstruse Abstruse CI], [https://appcenter.ms/ Appcenter], [https://assertible.com/ Assertible], [https://github.com/bosondata/badwolf Badwolf], [http://bitrise.io/ Bitrise], [https://buildkite.com/ Buildkite], [https://www.chronoci.com/ ChronoCI], [https://www.codacy.com/ Codacy], [https://codefresh.io/ Codefresh], [https://www.codeship.io/ Codeship], [http://concourse.ci/ ConcourseCI], [https://continuousphp.com/ ContinuousPHP], [https://drone.io/ Drone], [https://ebertapp.io/ Ebert], [https://gocd.io/ GoCD], [https://houndci.com/ HoundCI], [https://nixos.org/hydra/ Hydra], [https://probo.ci/ Probo.CI], [https://semaphoreci.com/ Semaphore], [https://www.shippable.com/ Shippable], [https://www.jetbrains.com/teamcity/ TeamCity], [https://www.visualstudio.com/team-services/ VSTS], [https://app.wercker.com/ Wercker]