Kong

Kong gained massive popularity by being an open-source, incredibly fast API gateway built on top of NGINX. As the software industry shifted away from giant monolithic applications and towards microservices, Kong emerged as the standard tool for managing the chaotic web of internal APIs communicating with each other. Speed is Kong's primary selling point. Because it operates at the core infrastructure layer and utilizes the Lua scripting language over NGINX, it can route API traffic with sub-millisecond latency. This makes it a favorite for modern, hyper-scalable tech companies running massive Kubernetes clusters. The open-source version functions strictly via command line and RESTful configuration, making it highly attractive to DevOps engineers who want to automate their infrastructure using "Infrastructure as Code." Kong's enterprise tier adds a visual dashboard, advanced security plugins, and dedicated developer portals, but the core routing engine remains the exact same open-source technology that processes billions of transactions daily across the internet.