Many cities have started to create open data websites to post their collected geospacial data.  These sites usually allow bulk download of their datasets in standard machine-processable file formats, which is key.  Some have visualizations of the data too, though this is a secondary feature to open data. These sites are either created by the city, or they use certain vendors to provide easy, out-of-the-box solutions for formatting, opening, and mapping their raw data.

UPDATE – Oct 28, 2013

Since creating this post a number of other organizations have started keeping a list of cities, counties, and states with open data portals. As such I’m not going to update this page any more. Please visit the following 3 pages to see a list and either edit their pages or connact them to have them add new ones.

1. Sunlight Foundation Open Data Map
2. Civic Commons List
3. The Federal Government’s List of Open Data Cities

——- List from Nov 2012 ——-

Using CKAN

• Lexington
• Colorado: Denver, Arvada, Boulder, Castle Rock

Using Socrata

• Austin
• Baltimore
• New York City
• San Francisco
• Seattle
• Chicago
• Austin
• New Orleans
• Sommerville, MD
• Honolulu

Using Junar

• Palo Alto

Using Open Data Catalog

• San Diego
• Philadelphia

Using Custom Code

• Atlanta
• Portland
• Boston
• Washington D.C.
• Ann Arbor
• Louisville

Any that we missed? Let us know in the comments and we will keep this post updated.

Updated: Nov 20, 2012 – Colorado, Lexington, Honolulu.