Agile software development methods are now well established in many commercial organizations and are starting to make inroads into government contexts. There are reports of software development projects using Agile methods that achieve significantly higher levels of productivity and quality compared with projects that used traditional methods. When it comes to brand new “start from scratch” software projects, a wealth of information, advice, training, and literature exists to help guide practitioners and speed them along the path to agility. Unfortunately, most such publicly available resources have relatively little to say when it comes to legacy systems. However, there is a small but growing amount of evidence that agile practices can yield compelling benefits for legacy projects—even those that have been previously successful using traditional methods. Our experience suggests that agile practices need to be customized and introduced in a different order into a legacy project. This presentation provides an analysis of the differences between legacy projects and new software development and the implications for the adoption of agile methods.