From Citizendium, the Citizens' Compendium
Serial Box is a monthly compilation of stolen, hacked and otherwise illegally obtained serial numbers for many applications. Serial Box, the successor to Surfer's Serials, is the most popular serial compilation for the Mac OS X operating system. Although it has serials for major Windows compatible applications, the majority of serials are for Macintosh applications. The application offers several options designed to ease locating and inserting illegal serial numbers. The reasons for doing this is to prevent multiple copies of the same serial number on a network to be detected, and to have an ostensibly valid serial number for obtaining updates.
Serials for the Serial Box database are gathered from messages on the alt.binaries.mac.serials newsgroup, emails to database authors and various other sources. The database file generated is in XML format and averages about 1.7 megabytes in size.