Istio is an open platform for providing a uniform way to integrate microservices, manage traffic flow across microservices, enforce policies and aggregate telemetry data. Istio's control plane provides an abstraction layer over the underlying cluster management platform, such as Kubernetes, Mesos, etc.
Kong is a scalable, open source API Layer (also known as an API Gateway, or API Middleware). Kong controls layer 4 and 7 traffic and is extended through Plugins, which provide extra functionality and services beyond the core platform.
It is the front door for all requests from devices and websites to the backend of the Netflix streaming application. As an edge service application, It is built to enable dynamic routing, monitoring, resiliency, and security. Routing is an integral part of a microservice architecture.
linkerd is an out-of-process network stack for microservices. It functions as a transparent RPC proxy, handling everything needed to make inter-service RPC safe and sane--including load-balancing, service discovery, instrumentation, and routing.
It is open source, production quality, framework for developing RESTful Web Services in Java that provides support for JAX-RS APIs and serves as a JAX-RS (JSR 311 & JSR 339) Reference Implementation. It provides it’s own API that extend the JAX-RS toolkit with additional features and utilities to further simplify RESTful service and client development.