Science.gov is a free, integrated single-search gateway to reliable science and technology information from 17 organizations within 13 federal science agencies. In this new 5.0 version,  launched on Sept. 15th, there are 7 additional portals or databases that quadruple its content.  New content includes patents, toxicology data, e-prints from the Dept. of Energy and OSTI, and journal archives from PubMed Central, and Cancer.gov.

The search engine is improved with clustering technology, and Science.gov now provides links to science news, the EurekAlert! and Wikipedia. 

"Science.gov is hosted by DOE’s Office of Scientific and Technical Information (OSTI), within DOE’s Office of Science. In addition to DOE, Science.gov is supported by contributing members of the Science.gov Alliance, including the Departments of Agriculture, Commerce, Defense, Education, Health and Human Services, and the Interior, the Environmental Protection Agency, the Government Printing Office, the Library of Congress, the National Aeronautics and Space Administration and the National Science Foundation, with support from the National Archives and Records Administration."

From Tim Byrne at osti/gov