The best Con­tin­u­ous In­te­gra­tion Tools

With con­tin­u­ous in­te­gra­tion (CI), software de­vel­op­ers avoid having to overcome a time-consuming and trou­ble­some in­te­gra­tion phase at the end of a project. Instead of bringing all in­di­vid­ual elements together at the end, CI inserts every change directly into the code base. This requires dis­ci­pline and efficient processes – otherwise CI may do more harm than good. Specially designed software makes the entire process simpler.

Partly com­plete­ly in­de­pen­dent, and partly in com­bi­na­tion with other well-known ap­pli­ca­tions, CI tools offer support in building a repos­i­to­ry, testing and building, version control, and of course in con­tin­u­ous in­te­gra­tion itself.

Many different con­tin­u­ous in­te­gra­tion tools are now available on the internet, all of which have different features designed to help de­vel­op­ers implement con­tin­u­ous in­te­gra­tion in various ways. But it’s not just the func­tion­al­i­ty of CI tools that dif­fer­en­ti­ate them, they also vary sig­nif­i­cant­ly in price and licensing options. While many are open source and free of charge, some providers also offer com­mer­cial tools. Here is an overview of some of the most popular and best con­tin­u­ous in­te­gra­tion tools and their re­spec­tive features and functions.

Jenkins is perhaps one of the most well-known con­tin­u­ous in­te­gra­tion tools on the market. Since 2005 (still named Hudson at the time), the software has been con­tin­u­ous­ly developed. The Java-based program offers many functions that not only help with CI, but also with con­tin­u­ous delivery and con­tin­u­ous de­ploy­ment.

• Java based
• Runs in an EJB container
• Over 1000 plugins
• Also supports con­tin­u­ous delivery and con­tin­u­ous de­ploy­ment
• Can be combined with many different version man­age­ment systems
• Control over GUI (web based), REST API, or command line commands
• Cloud hosting possible
• Free
• Open source (MIT license)

Those who work with GitHub will probably love Travis CI, since this CI tool works seam­less­ly with the popular version control system. The software can be con­fig­ured with a simple YAML file, which you place in the root directory of the de­vel­op­ment project. GitHub alerts Travis CI to any changes made to the repos­i­to­ry and keeps the project up to date.

• Ruby based
• Platform in­de­pen­dent
• Works with GitHub
• Con­fig­u­ra­tion with YAML files
• Free for open source projects
• Costs $69-489 per month for com­mer­cial projects
• Open source (MIT license)

The company Atlassian, which now also offers a file hosting service called Bitbucket, has offered the Bamboo con­tin­u­ous in­te­gra­tion tool since 2007. Beyond assisting de­vel­op­ers with in­te­gra­tion, Bamboo also offers features for de­ploy­ment and release man­age­ment. The tool boasts an easy-to-use web interface.

• Java based
• Platform in­de­pen­dent
• Easy in­te­gra­tion with other Atlassian products
• Plenty of add-ons
• Possible to run several tests si­mul­ta­ne­ous­ly
• Com­mu­ni­ca­tion via web interface and REST-API
• Free for open source projects, non-profit or­ga­ni­za­tions, and school classes
• Otherwise costs a one-time fee of $10-110,000, depending on the number of servers required

GitLab CI is a component of the well-known version man­age­ment system GitLab. In addition to con­tin­u­ous in­te­gra­tion, GitLab also offers con­tin­u­ous de­ploy­ment and con­tin­u­ous delivery. Like Travis CI, GitLab CI uses a YAML for con­fig­u­ra­tion. In addition, working with the software is rel­a­tive­ly easy.

• Component of GitLab
• Based on Ruby and Go
• Con­fig­u­ra­tion with YAML files
• Also supports con­tin­u­ous delivery and con­tin­u­ous de­ploy­ment
• Open core
• Self-hosting and cloud hosting available
• Free version has limited features
• Prices for other versions are $3-99 per month and user

The CircleCI con­tin­u­ous in­te­gra­tion tool works together with both GitHub and Bitbucket. Testing is run via con­tain­ers or a virtual machine. CircleCI places great emphasis on smooth and seamless de­vel­op­ment processes, so bug-free builds can be au­to­mat­i­cal­ly deployed to other en­vi­ron­ments.

• Con­fig­u­ra­tion with YAML files
• Also supports con­tin­u­ous de­vel­op­ment
• Self-hosting and cloud hosting available
• Runs in Docker con­tain­ers, Linux VMs, and macOS VMs
• Free for one container
• Otherwise costs $50-3150 per month

CruiseC­on­trol is one of the oldest con­tin­u­ous de­vel­op­ment tools on the market. It was launched as early as 2001 and has been con­tin­u­ous­ly developed ever since – by the con­tin­u­ous in­te­gra­tion pioneer Martin Fowler, among others. In addition to a straight­for­ward dashboard, users also have numerous plugins at their disposal to make their work easier.

• Java based
• Platform in­de­pen­dent
• Web-based dashboard
• Ruby (CruiseC­on­trol.rb) and .NET (CruiseC­on­trol.NET) versions available
• Open source (BSD license)
• Free

The Codeship CI tool belongs to CloudBee, which also has Jenkins in its portfolio. The program is available in two different versions: The Basic version offers an easy-to-use web interface, while the Pro version is con­fig­ured with files in the repos­i­to­ry. If you want to work with a Docker container, you require the Pro version.

• Web interface (Pro)
• Con­fig­u­ra­tion files in the repos­i­to­ry (Pro)
• Supports Docker (Pro)
• Free for up to 100 builds per month for one test pipeline
• Otherwise costs $75-1,500 per month

The TeamCity software is par­tic­u­lar­ly im­pres­sive because of its gated commits, which it uses to test changes to the code before they are im­ple­ment­ed into the mainline. Only when the source code is error-free does it become part of the code base for the entire team. TeamCity runs the tests au­tonomous­ly in the back­ground so the developer can continue working in the meantime.

• Java based
• Platform in­de­pen­dent
• Gated commits
• Free 100 builds with three build agents
• Otherwise costs a one-off payment of $299-21,999
• 50% discount for startups and free for open source projects

All CI tools have different ad­van­tages and dis­ad­van­tages. With the help of the overview table below, you can see at a glance which programs are most suitable for your needs. For example, you can quickly see whether the service also supports con­tin­u­ous delivery or offers cloud hosting.