ModSecurity - ModSecurity is an Open Source web application firewall developed by Trustwave's SpiderLabs.
nginx - A high performance free open source web server powering busiest sites on the Internet.
AWS WAF - AWS WAF is a web application firewall that helps protect your web applications from common web exploits.
AWS Elastic Load Balancing - Amazon ELB automatically distributes incoming application traffic across multiple Amazon EC2 instances in the cloud.
Cloudflare WAF - Whether you want automatic WAF protection from known vulnerabilities or have custom WAF rules, our real-time platform can do it.
Google Cloud Load Balancing - Google Cloud Load Balancer enables users to scale their applications on Google Compute Engine.