... During the past year the Astrophysics Data System has set up two mirror sites for the benefit of users around the world with a slow network connection to the main ADS server in Cambridge, MA. ... The software used to perform the actual mirroring of the databases consists of a main program running on the ADS master site initiating the mirroring procedure, and a number of scripts, run on the mirror sites, which perform the transfer of files and software necessary to update the database. ...