DEMOS-Budget is an Internet platform that makes it possible for citizens to take part in municipal budget planning. Using genuine figures as its basis, the application displays an actual budget. Members of the public can draw up their own budgets and adjust the initial one as they see fit. Each change to a budget item is added to or deducted from the total budget in real time. The system’s only immutable rule is that the total sum of money available may not and cannot be exceeded. Any increase in spending must be balanced by savings elsewhere.