ModSecurity - ModSecurity is an Open Source web application firewall developed by Trustwave's SpiderLabs.
ironbee - Universal web application firewall engine
AWS WAF - AWS WAF is a web application firewall that helps protect your web applications from common web exploits.
Cloudflare WAF - Whether you want automatic WAF protection from known vulnerabilities or have custom WAF rules, our real-time platform can do it.
open-appsec - open-source machine learning based WAF for Kubernetes Ingress, NGINX, Envoy and API Gateways
Barracuda Web Application Firewall - Barracuda Web Application Firewall offers security and DDoS protection against automated & targeted attacks.