NGINX
The commercial ingress controller developed and maintained by F5 NGINX.
https://www.nginx.com/products/nginx-ingress-controller/Features
Alternatives to NGINX:
Contour
Contour is an open source Kubernetes ingress controller providing the control plane for the Envoy edge and service proxy.
Emissary Ingress
Emissary-Ingress is an open-source Kubernetes-native API Gateway + Layer 7 load balancer + Kubernetes Ingress built on Envoy Proxy. Emissary-ingress is a CNCF incubation project (and was formerly known as Ambassador API Gateway).
HAProxy Ingress
Fast, Reliable and Highly customizable ingress controller based on HAProxy.
Ingress-NGINX
The open source ingress controller based on the open source NGINX server and maintained by the Kubernetes community.
Istio Ingress
An open source ingress controller based on Istio. Not to be confused with Istio's Gateway API, which is recommended to make use of the full feature set that Istio offers.
Traefik Ingress
An open source ingress controller based on Traefik.