What CI Tools Do You Use?
Recently, we started using RunCodeRun, a new hosted continuous integration (CI) system. If you're not familiar with the concept of CI and automated build tools, Martin Fowler's classic article on the subject is probably the best starting point. Essentially the CI workflow stresses that solid software development practices rely on having a fully automated and instantly reproducible build system, that includes testing, and runs many times a day. Ideally whenever a commit is made to the project mainline.
RunCodeRun is a Ruby-specific CI tool that plugs right into GitHub (which is conveniently where we're already hosting our project code) with almost no configuration. Whenever a commit is made, RCR automatically checks out the latest version of the master branch and aattempts to run the associated test suite. It then optionally notifies our development team with the results. It's still in beta right now (sign up for an invite on the website) and has a few kinks but for the most part it's very nice; the interface is minimalist and simple, just the way I like it.
Having a CI system like this in place is great for a distributed team such as ours, because it can be configured to let them know if someone has unwittingly broken a build (via email, campfire, etc). It also means that any code checked into the mainline is, at any point, building, and that tests are all passing. It's a great litmus test and more than anything, helps to keep developers and rogue commits in line.
I don't always use CI when I work on software development projects, for better or for worse. But when working with a distributed team, particularly on an OSS project where there isn't a well-defined project manager role, it's a huge advantage. RCR is a nice (new) option simply because it's hosted, and therefore it's one less thing your team has to worry about maintaining or spending precious cycles configuring. The tradeoff, of course, is some amount of flexibility.
If you need more flexibility, there are a number of established players in this space that offer that, including some well-loved OSS packages. CruiseControl is probably the most popular of these. There are variants of CruiseControl available for different languages and environments, including a Java, .NET version (CruiseControl.NET) and a Ruby version (CruiseControl.rb), whereas RCR currently only supports Ruby-based projects at the moment.
In any case, I'm certainly glad to see that options like this are becoming easier for casual and, in particular, open source projects. The simpler we can make these tools to use, the more effective and widespread they become. The less time we can spend on painful integration woes, the more we can spend building quality software. I'd love to hear what tools in this vein you are personally using, if anything at all (!).