OctopusWAF
Web application firewall in C language uses libevent
OctopusWAF is a open source Web application firewall, is made in C language uses libevent to make multiple connections. Event-driven architecture is optimized for a large number of parallel connections (keep-alive) which is important for high performance AJAX applications. This tool is very light, you can deploy in any please, this resource turn perfect to protect specific endpoint that need a custom protection.