Snort 1.3, the lightweight network intrusion detection system. This version has a number of new features, including four new command line switches, three new rule options, two new rule operators, performance enhancements, and bug fixes. The official Snort homepage is here
You can download it from the following link: https://packetstormsecurity.com/files/download/16038/snort-1.3.tar.gz
Source: https://packetstormsecurity.com/files/16038/snort-1.3.tar.gz.html