The leading software for creating digital maps. For help tutorials, visit this page.

Create, annotate, store and share maps. View Google support documentation here.

Explore and map Allentown data across different categories.

Comprehensive state government data.

This site provides access to all of PennDOT's published GIS data that you can map, style, chart, download or share.

PASDA, PA's official public access geospatial information clearinghouse, provides free public access to geospatial data and information by, for, and about the Commonwealth of Pennsylvania.

WPRD hosts datasets from Allegheny County, the University of Pittsburgh and other public sector agencies, academic institutions, and non-profit organizations.

The datacommons@psu was developed to provide a resource for data sharing, discovery, and archiving for the Penn State research and teaching community.

The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the Executive Branch of the Federal Government.

"The definitive place to explore US public data" (website description).

Comprehensive aggregate of NPS data.

List of open data sources by state compiled by UMD.

Provides datasets across industries for US city areas.

Searchable index of ArcGIS datasets.

Boundaries of subnational administrative districts.
Downloadable in shapefile, geodatabase, KMZ, or R formats.

Generalized boundaries for political and physical features in shapefile format. Useful for map-making but not for applications requiring precision.

Extracts from crowd-sourced OpenStreetMap data.

Believed to be the most accurate available worldwide international boundary vector line file.