A type of chart used in agile methodologies to measure the amount of work remaining against time.
A typical burn-down chart will plot outstanding work (number of features, ideal days, team days etc.) on the vertical axis, and time (days, iterations, sprints etc.) on the horizontal axis.
Burn-down charts are very useful to measure actual work progress against ideal work progress, and detect potential schedule overruns and work-pace issues early on.
see also: agile methodology, scrum