Appwrite is an end-to-end backend server for Web, Mobile, Native, or Backend apps packaged as a set of Docker microservices. Appwrite abstracts the complexity and repetitiveness required to build a modern backend API from scratch and allows you to build secure apps faster.

Using Appwrite, you can easily integrate your app with user authentication and multiple sign-in methods, a database for storing and querying users and team data, storage and file management, image manipulation, Cloud Functions, and more services.

The open-source notifications infrastructure. A fully-featured microservice to send SMS, E-mail, Slack and Push notifications. Embeddable notification center for React with real-time updates, content management, and much more...

Backstage is an open platform for building developer portals. Powered by a centralized software catalog, Backstage restores order to your microservices and infrastructure and enables your product teams to ship high-quality code quickly — without compromising autonomy.

Backstage unifies all your infrastructure tooling, services, and documentation to create a streamlined development environment from end to end.

Fast, easy and reliable testing for integrating web apps, APIs and microservices. Pact is a code-first tool for testing HTTP and message integrations using contract tests. Contract tests assert that inter-application messages conform to a shared understanding that is documented in a contract. Without contract testing, the only way to ensure that applications will work correctly together is by using expensive and brittle integration tests.

Dapr is a portable, serverless, event-driven runtime that makes it easy for developers to build resilient, stateless and stateful microservices that run on the cloud and edge and embraces the diversity of languages and developer frameworks.

NATS.io is a simple, secure and high performance open source messaging system for cloud native applications, IoT messaging, and microservices architectures.

Temporal is a microservice orchestration platform which enables developers to build scalable applications without sacrificing productivity or reliability. Temporal server executes units of application logic, Workflows, in a resilient manner that automatically handles intermittent failures, and retries failed operations.

Your new microservice development environment friend. This CLI tool allows you to define a configuration to work with both local applications (Go, NodeJS, Rust or others) and forward some other applications over Kubernetes in case you don't want to run them locally.

Go is a great general-purpose language, but microservices require a certain amount of specialized support. RPC safety, system observability, infrastructure integration, even program design — Go kit fills in the gaps left by the standard library, and makes Go a first-class language for writing microservices in any organization.

Conductor is an orchestration engine that runs in the cloud.
Netflix built Conductor to help orchestrate microservices based process flows with the following features:

Allow creating complex process / business flows in which individual task is implemented by a microservice.
A JSON DSL based blueprint defines the execution flow.
Provide visibility and traceability into the these process flows.
Expose control semantics around pause, resume, restart, etc allowing for better devops experience.
Allow greater reuse of existing microservices providing an easier path for onboarding.
User interface to visualize the process flows.
Ability to synchronously process all the tasks when needed.
Ability to scale millions of concurrently running process flows.
Backed by a queuing service abstracted from the clients.
Be able to operate on HTTP or other transports e.g. gRPC.

Zipkin is a distributed tracing system. It helps gather timing data needed to troubleshoot latency problems in microservice architectures. It manages both the collection and lookup of this data. Zipkin’s design is based on the Google Dapper paper.

Applications are instrumented to report timing data to Zipkin. The Zipkin UI also presents a Dependency diagram showing how many traced requests went through each application. If you are troubleshooting latency problems or errors, you can filter or sort all traces based on the application, length of trace, annotation, or timestamp. Once you select a trace, you can see the percentage of the total trace time each span takes which allows you to identify the problem application.

Jaeger, inspired by Dapper and OpenZipkin, is a distributed tracing system released as open source by Uber Technologies. It is used for monitoring and troubleshooting microservices-based distributed systems, including:

Distributed context propagation
Distributed transaction monitoring
Root cause analysis
Service dependency analysis
Performance / latency optimization

Cilium is open source software for providing and transparently securing network connectivity and loadbalancing between application workloads such as application containers or processes. Cilium operates at Layer 3/4 to provide traditional networking and security services as well as Layer 7 to protect and secure use of modern application protocols such as HTTP, gRPC and Kafka. Cilium is integrated into common orchestration frameworks such as Kubernetes and Mesos.

Otoroshi is a modern http reverse proxy with a thin layer of api management written in Scala and developped by the MAIF OSS team. Otoroshi is designed to handle all the calls to and between your microservices without service locator and let you change configuration dynamicaly at runtime.

Izanami is a shared configuration, feature flipping and A/B testing service perfectly well suited for micro services environment written in scala and developed by the MAIF OSS team.
Izanami provides a friendly UI for non-tech users as an HTTP REST API you can call using you favorite language.

Izanami also provides first class integration. Java, Scala, Node and React and CLI clients are available to integrate Izanami with your application.

Istio is an open platform that provides a uniform way to connect, manage, and secure microservices. Istio supports managing traffic flows between microservices, enforcing access policies, and aggregating telemetry data, all without requiring changes to the microservice code.

Kraken is the first and only multi-processed, multi-threaded, fault-tolerant framework for PHP. It has been written to provide easy and reliable API for creating distributed applications using PHP.

A curated list of Microservice Architecture related principles and technologies.

Envoy is an L7 proxy and communication bus designed for large modern service oriented architectures.

IronFunctions is an open source serverless platform, or as we like to refer to it, Functions as a Service (FaaS) platform that you can run anywhere.