One of the best places in the area to find maps is at the Free Library of Philadelphia's main branch at 1901 Vine Street. Over 130,000 historical and current maps are available and are particularly strong for the Philadelphia area. An extensive aerial photograph collection of the Delaware Valley shows how the landscape of the area has changed over time.
OpenDataPhilly is a portal that provides access to over 175 data sets, applications, and APIs related to the Philadelphia region. Built by Azavea, a Philadelphia-based Geographic Information Systems (GIS) software firm, it is now operated by the Philadelphia Public Interest Information Network, a Philadelphia-based non-profit organization. OpenDataPhilly is based on the idea that providing free and easy access to data information encourages better and more transparent government and a more engaged and knowledgeable citizenry.
OpenDataPhilly includes both municipal and non-municipal data and enables users to search for and locate data sets based on keyword and category searches. For each data set, application, or API, we’ve included accompanying information about the origins, update frequency, and other specifics of the data. The record for each data source also includes links for downloading the data or accessing the application or API.