The Lidar Data Exchange Format is a binary file format for the interchange of LIDAR (Light Detection and Ranging) optical remote sensing data.
Specifications available at http://www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html
Format information supplied by the Geospatial Multistate Access and Preservation Partnership (GeoMAPP), a grant funded collaboration involving North Carolina, Kentucky, Utah, and Montana state archives, and sponsored by the National Digital Information Infrastructure Preservation Program (NDIIPP) of the Library of Congress.