Istio's journey began on May 2017 with its first alpha release of 0.1. Istio's 1.0 production-level release launched in July 2018. Since its inception, 80+ releases of Istio have been published, which shows the dynamism of this trendy open source project. At the time of writing, it is the most popular service mesh framework, with 18,000+ stars, 3,000+ forks, and 100+ companies around the world contributing to it. It has an active developer community around it.

Before the service mesh concept came to light, libraries such as Netflix's Hystrix (https://github.com/Netflix/Hystrix) and Twitter's Finagle (https://github.com/twitter/finagle) were popular for serving Java-based programs. Then came Lyft's Envoy (https://github.com/envoyproxy/envoy), which changed the dynamics as it could run as a sidecar proxy and hence provided a  language-agnostic decoupled implementation. 

The community maintains the Istio project at http://istio.io. Istio is a very feature-rich function framework that provides comprehensive service mesh capabilities. 

Istio initially started with different technologies from IBM, Google, and Lyft (for more information, go to https://github.com/istio/community#istio-authors):

• IBM's research project, algam8 (Rothert), provides a programmable control plane that has unified traffic routing. This control plane helps with blue/green testing, canary releases, and testing the resilience of services against failures.
• Google provides a programmable control plane that has policies for rate limits, authentication, and ACLs. The control plane gathers telemetry data from various services and proxies.
• Lyft provided Envoy (https://envoyproxy.io), which is a sidecar for a microservice. Envoy is a graduated project from CNCF.

Now, let's go through Istio's architecture.