Orleans
A .NET framework for building distributed apps using 'grains', objects that stay available across many servers
- Stars
- 10.9k
- Forks
- 2.2k
- Licence
- MIT
- Language
- C#
- Last update
- 4 days ago
- Type
- Library
What it is
Orleans is a framework for building distributed applications in C#, the kind that run across several servers or in the cloud. It extends familiar .NET ideas like objects, interfaces, and async/await to multi-server setups. Its core unit, the grain, is an object with a stable identity that the runtime can activate, move, and deactivate as needed, so developers can write code as if all grains were always in memory.
- Modeling each IoT device as a grain that keeps its latest data in memory, as the README's thermostat example shows
- Building a Web backend where frontends call grains through strongly-typed interfaces
- Persisting grain state to a storage system of your choice with state.WriteStateAsync()
- Coordinating changes across multiple grains using distributed transactions
Great for
- C# and .NET developers building scalable backend services
- Teams modeling many independent entities, such as devices or users, as stateful objects
- Developers moving from single-server apps to distributed systems
- Projects that need persistence or distributed transactions across grains
Not ideal for
- Developers who work in languages other than C#/.NET, since the framework is built for .NET (the README does not describe other language bindings)
- Small single-server apps with no scaling needs, where the added concepts may not pay off
- Teams that need to understand every low-level detail of their cluster, since the runtime manages placement and recovery for you
How to get it
- 1
Install with a package manager
You'll need: .NET (version not specified in the README excerpt)
Clone the repository
git clone https://github.com/dotnet/orleans - 2
Run it
- Install .NET and create a project
- Add the Orleans NuGet packages (Microsoft.Orleans.Core is named in the README badge)
- Define a grain interface that extends IGrainWithStringKey and a class that implements it
- Call the grain from a client using client.GetGrain<T>(id)
- Read the Orleans docs for the sample projects and the full setup
- 3
Get the most out of it
- Use grain persistence to store state in any storage system you choose
- Use reminders (persistent timers) for work that must survive restarts
- Use streams to observe time-series data, as in the README's IoT example
- Use distributed ACID transactions when several grains must change together
Downloads
Strengths
- Stable grain identities let callers reach an object without knowing which server hosts it
- Grain state is kept in memory while active, which the README says lowers latency and load on data stores
- Works from a single on-premises server up to a multi-server cluster
Trade-offs
- The programming model is unfamiliar at first, and the README is a high-level overview rather than a tutorial
- The README's examples omit persistence, so state handling requires reading the separate docs
- Cluster behavior and operations are not covered in this excerpt, so production setup needs more research
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| orleans (this) | 10.9k | Library | intermediate | 4 days ago | C# and .NET developers building scalable backend services |
| go-zero | 33.4k | Library | intermediate | 5 days ago | Go developers building REST APIs or microservices |
| kratos | 26k | Library | intermediate | 4 days ago | Go developers building a set of backend services that talk over HTTP or gRPC |
| effect | 17.5k | Library | advanced | 4 days ago | Teams building large or long-lived TypeScript back-end services |
| BenchmarkDotNet | 11.5k | Library | intermediate | 5 days ago | .NET developers who want to compare two or more implementations of a method |
| conc | 10.4k | Library | intermediate | 2 months ago | Go developers who use goroutines in long-running services |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.