- American Archive of Public Broadcasting: A collaboration between the Library of Congress and WGBH in Boston, this free resource provides access to approximately 40,000 hours of radio and TV programs selected by more than 100 public broadcasting stations nationwide.
- Chilton Library
- Curationist: Launched by the MHz Foundation, this nonprofit project is designed to connect arts and culture communities and provide users with open access to global cultural resources.
- InfoPlease.com
- Legal & Business Forms
- The Lens: A flagship project of the social enterprise Cambia, the Lens makes the most of metadata, integrating multiple identifiers and sources so that more than 225 million scholarly works, 127 million patent records, and 370 million patent sequences can be searched, collated, and analyzed.
- Lots of Maps
- Mendeley Data: This free cloud-based communal repository provides a place for users to store and share data to enable citation.
- National Conference of State Legislatures: Research and Policy: The National Conference of State Legislatures (NCSL), a bipartisan organization serving U.S. law and policymakers, provides objective fact- and evidence-based research across 1,400-plus issue areas, including agriculture, budget and taxes, education, health care, immigration, and more.
- Open Knowledge Maps: Geared toward teachers, students, and researchers, this open-source search engine for scientific knowledge provides users with a visual map of their results, making it easier to identify relevant content and concepts.
- RefDesk
- Scholarcy: Designed for scholars, researchers, librarians, and students, this site provides users with a robust suite of tools for summarizing and annotating articles.
- WolframAlpha: This wide-ranging ready reference tool provides access to a phenomenal amount of data and information through simple factual searches.
- World Book Encyclopedia
- World Radio Map: Listing AM/FM radio stations by their broadcasting frequencies, this site allows users to tune in from their computer or mobile device.
Thanks for help curating this list goes to Sarah Hashimoto, Editor, LJ Reviews & Gary Price, LJ INFOdocket