"The National Archives is releasing documents previously withheld in accordance with the JFK Assassination Records Collection Act. The vast majority of the Collection (88%) has been open in full and released to the public since the late 1990s. The records at issue are documents previously identified as assassination records, but withheld in full or withheld in part. [...] These releases include FBI, CIA, and other agency documents (both formerly withheld in part and formerly withheld in full) identified by the Assassination Records Review Board as assassination records."
National Archives and Records Administration: http://www.archives.gov/