Internet Archive is a non-profit library of millions of free books, movies, software, music, websites, and more.
The Wayback Machine is an initiative of the Internet Archive, which provides access to over 477 billion web pages saved over time (since 1996).
Library Of Congress is an almost endless source of research information. Begin with the Research and Reference Services page, which includes links to Books, Pamphlets, Journals, Newspapers and other serial publications, Photographs, Children's Literature, Geography & Maps, Rare Book & Special Collections, Research Guides, Digital Collections & Services all from earliest history to the present day.
The CIA World Factbook The World Factbook provides information on the history, people, society, government, economy, energy, geography, communications, transportation, military, and transnational issues for 267 world entities.
The United States Patent and Trademark Office (USPTO) is another neglected source of knowledge. While FI does not support the concepts of patents or copyrights, the details of every machine, electronic device, and chemical process ever patented is available through the USPTO. To find particular information, begin with a patent searching here.
Artcyclopedia an almost exhaustive resource of information on all aspects of art with links to museums worldwide where works by over 8,200 artists can be viewed. Painters and sculptors are emphasized but also includes photographer, decorative artists, and architects.