Raptor is a web application firewall written in C that uses DFA to block SQL injection, cross site scripting, and path traversals.
You can download it from the following link: https://packetstormsecurity.com/files/download/161694/raptor_waf-Raptor_v06.2.tar.gz
Source: https://packetstormsecurity.com/files/161694/Raptor-WAF-0.62.html