PI gateways play a crucial role in managing, securing, and optimizing communication between different microservices or between clients and servers. Here’s a list of both commercial and open-source API gateways:

Commercial API Gateways:

1. Apigee (Google Cloud API Management):
   • Website: Apigee
2. AWS API Gateway (Amazon API Gateway):
   • Website: AWS API Gateway
3. Azure API Management:
   • Website: Azure API Management
4. IBM API Connect:
   • Website: IBM API Connect
5. MuleSoft Anypoint Platform:
   • Website: MuleSoft Anypoint Platform
6. Kong Enterprise:
   • Website: Kong Enterprise
7. Tyk:
   • Website: Tyk

Open-Source API Gateways:

1. NGINX:
   • Website: NGINX
2. Express Gateway:
   • GitHub: Express Gateway
3. Kong (Community Edition):
   • GitHub: Kong
4. Tyk Gateway (Open Source Edition):
   • GitHub: Tyk Gateway
5. KrakenD:
   • GitHub: KrakenD
6. Traefik:
   • GitHub: Traefik
7. Ambassador API Gateway:
   • GitHub: Ambassador
8. Gloo Edge:
   • GitHub: Gloo Edge

It’s important to evaluate the specific requirements, features, and licensing considerations when choosing between commercial and open-source API gateways. The choice may depend on factors such as scalability, support, ease of integration, and available features.