The City of Madison’s Open Data Portal can be found at https://data.cityofmadison.com/. This is a separate initiative from the Madison Neighborhood Indicators Project, which is hosted by the UW-Madison’s Applied Population Laboratory.
From Government Technology, 1/8/2013:
On Jan. 8, city officials announced the launch of its open data ordinance and a more accessible open data platform. Thus far, only one other city in the country, New York City, has implemented an ordinance mandating widespread government release of data, according to officials.
The city, officials said, is making open data projects a high priority. The new ordinance will require agencies to eventually release most of their data in raw format and make it available for download through the city’s new open data Web portal.
Though the city made open data available in the past, the effort was far less comprehensive and the data was not in a format that developers could easily use, said CIO Paul Kronberger. “We recognize that this data has been created with public funds,” he said, “so it rightfully belongs to the public and should be made available to the public.”
Read more: Madison, Wis. Launches Open Data Platform