  This paper describes the image stacks and catalogs of the CFHT Legacy Survey
produced using using the MegaPipe data pipeline at the Canadian Astronomy Data
Centre. The Legacy Survey is divided into to two parts: The Deep Survey
consists of 4 fields each of 1 square degree, with magnitude limits of u=27.5,
g=27.9, r=27.7, i=27.4, and z=26.2, and contains 1.6 million sources. The Wide
Survey consists of 171 square degree pointings split over 4 fields, with
magnitude limits of u=26.0, g=26.5, r=25.9, i=25.7, and z=24.6, and contains 30
million sources. This paper describes the calibration, image stacking and
catalog generation process. The images and catalogs are available on the web
through several interfaces: normal image and text file catalog downloads, a
Google Sky interface, an image cutout service, and a catalog database query
service.

Cosmology and Nongalactic Astrophysics