In the open source world, this is often described under the "release early, release often" mantra. But it's not always followed in the open source world. So you have projects that go long periods of times without a release, where users are told to pull the latest from CVS (hello Jakarta Commons!). That makes it hard to have confidence in the project or to have the project move forward. I think that open source projects should try to do regular time-boxed releases, cutting features in order to make the release dates. There can be exceptions for features that are bigger than a single time-box, but these ought to be the exception rather than the rule. Predictability is good when you are a software user. It makes me feel better when I see that a project releases regularly. Nightly builds are good, but for a lot of projects, I could see semimonthly or monthly time-boxes working pretty well.