Today, I’d highlight two recent improvements to the label and matrix projects.
When you have multiple slaves in your Hudson build farm, you can use labels to classify slaves by their capability/environment/architecture/etc. For example, your one slave might have “32bit” and “windows” label, while another one might have “linux”, “ubuntu”, and “64bit.” (with plugins like platform-labeler plugin, you can attach labels automatically, too.) Or if you do Selenium testing, you might add browser names as labels to indicate which slave has which browser available.
With such set up, you then specify that such and such jobs can be only run on such and such labels. For example, you might say your “test-foo” job requires the “windows” label, while your “compile-bar” job might require the “macos” label.