Chicago has released over 400 datasets using our data portal, which is located at http://data.cityofchicago.org. The portal will remain the primary way we release data to the public since it provides a great interface, easy way to download data, and the ability to make maps and graphs. The datasets posted on GitHub have an MIT License and which we hope will be widely used by open source projects, businesses, or non-profits. GitHub also allows an on-going collaboration with editing and improving data, unlike the typical portal technology. Because it's an open source license, data can be hosted on other services and we'd also like to see applications that could facilitate easier editing of geographic data by non-technical users.

Actually, our primary objective is to release data under an open source license so it can be used by businesses, non-profits, or open source projects, like OpenStreetMaps. Since we are releasing it on GitHub, we're going to experiment with the idea of merging changes made by users. This is an experiment for the community and government, we don't know how many pull requests will be made and the quality of those changes. We're excited to see what happens with data on GitHub to see if we can improve data quality.