Dev tools · alternatives · 2026

24 alternatives to Open-source non-blocking NIO Java HTTP Server

A full featured, stand-alone, high-performance HTTP server and client written entirely in plain Java - FusionAuth/java-http

This is an open-source Java HTTP server built on non-blocking NIO (New Input/Output) architecture. It is designed for developers who need a lightweight, asynchronous server for handling multiple concurrent connections… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Open-source non-blocking NIO Java HTTP Server launched in 2022; newer entries below may have overtaken it.

1. 1
   FusionAuth HTTP server▲5

   Open-source non-blocking NIO Java HTTP Server

   2022 · github.com · its alternatives →

2. 2
   ZeroHTTPd: A web server to teach Linux performance, with benchmarks▲472

   Articles in this series Part I. Iterative ServersPart II. Forking ServersPart III. Pre-forking ServersPart IV. Threaded ServersPart V. Pre-threaded ServersPart VI: poll-based serverPart VII: epoll-…

   2019 · unixism.net · its alternatives →

3. 3
   Hydrogen, a multithread non-blocking Linux server framework in Rust▲154

   Multithreaded, non-blocking Linux server framework in Rust - nathansizemore/hydrogen

   2016 · github.com · its alternatives →

4. 4IR
   Initial release of H2O, and why HTTPD performance will matter in 2015▲251

   Happy Holidays! Today I am delighted to announce the first release of H2O, version 0.9.0; this is a christmas gift from me. github.com/h...

   2014 · blog.kazuhooku.com · its alternatives →

5. 5
   SocketCluster.io – flexible open-source real-time server with pub/sub▲217

   Scalable open source pub/sub SDK with support for RPC, JWT authentication and Kubernetes — optimized for async/await

   2016 · socketcluster.io · its alternatives →

6. 6
   Deepstream.io – open-source real-time server with pub/sub and data sync▲301

   A realtime server for the modern web

   2016 · deepstream.io · its alternatives →

7. 7
   Pure C Asynchronous HTTP Framework▲80

   Asynchronous C networking library with HTTP server, WebSockets, reverse proxy, HTTP/2 gRPC client, TLS and event loop. - Softmotions/iwnet

   2022 · github.com · its alternatives →

8. 8
   Kyushu – A self-hostable WASM sandbox for JavaScript workers▲89

   A self-hostable Wasm sandbox for JavaScript workers.

   Jun 2026 · kyushu.dev · its alternatives →

9. 9
   Micro HTTP server in 22 lines of C▲223

   This post is from a protected account.

   2021 · twitter.com · its alternatives →

10. 10
    A pure bash web server. No netcat, socat, etc.▲224

    A purely bash web server, no socat, netcat, etc... - GitHub - dzove855/Bash-web-server: A purely bash web server, no socat, netcat, etc...

    2022 · github.com · its alternatives →

11. 112F
    2M fully loaded concurrent WebSockets▲158

    oatpp benchmark for 2 Million fully-loaded concurrent websocket connections.

    2019 · oatpp.io · its alternatives →

12. 12
    WSGI pure Python non-blocking HTTP2 server▲15

    Readable, simple and fast asynchronous non-blocking network apps - hivesolutions/netius

    2016 · github.com · its alternatives →

13. 13
    A pure C89 implementation of Go channels, with blocking selects▲271

    A pure C (-std=c89) implementation of Go channels, including blocking and non-blocking selects. - GitHub - rochus-keller/CspChan: A pure C (-std=c89) implementation of Go channels, including blocking and non-blocking selects.

    2023 · github.com · its alternatives →

14. 14
    Niquests – a simple HTTP library, a drop-in replacement for Requests▲44

    Drop-in replacement for Requests. Automatic HTTP/1.1, HTTP/2, and HTTP/3. WebSocket, and SSE included. WASI Supported. - niquests/README.md at main · jawah/niquests

    2024 · github.com · its alternatives →

15. 15
    go-nbd – A Pure Go NBD Server and Client▲113

    Hey HN! I just released go-nbd, a lightweight Go library for effortlessly creating NBD servers and clients. Its a neat tool for creating custom Linux block devices with arbitrary backends, such as a file, byte slice or what I'm planning to use it for, a tape drive. While there are a few partially abandoned projects like this out there already, this library tries to be as maintainable as possible by only implementing the most recent handshake revision and baseline functionality for both the client and the server, while still having enough support to be useful. I'd love to get your feedback :)

    2023 · github.com · its alternatives →

16. 16UT
    unsafehttp – tiny web server from scratch in C, running on an orange pi▲87

    Hey HN, I wanted to get more familiar with C programming, *nix socket programming and C compilation, so I wrote this "web" ""server"". It's running on a tiny SBC in my office, and there's as little as possible between you and it. Happy for you to try and break it, hopefully with something more interesting than a DoS though :) Please let me know if you find any issues.

    2025 · unsafehttp.benren.au · its alternatives →

17. 17
    A proof-of-concept FoundationDB based network block device backend▲192

    A totally proof-of-concept FoundationDB based network block device backend - dividuum/fdb-nbd

    2018 · github.com · its alternatives →

18. 18IA
    Inko – A safe and concurrent object-oriented programming language▲95

    2018 · inko-lang.org · its alternatives →

19. 19
    Test HTTP Requests without Mock Server▲29

    Java HTTP Client in OOP style. Contribute to Vatavuk/verano-http development by creating an account on GitHub.

    2019 · github.com · its alternatives →

20. 20
    Second State Serverless FaaS▲92

    High-performance serverless functions for Rust & WebAssembly

    2020 · secondstate.io · its alternatives →

21. 21
    Moustique – C++14 coroutine-based non-blocking IO on Linux▲68

    C++14 high performance non-blocking network IO (based on epoll + boost.context) - matt-42/moustique

    2018 · github.com · its alternatives →

22. 22
    Kameo – Fault-tolerant async actors built on Tokio▲105

    Hi HN, I’m excited to share Kameo, a lightweight Rust library that helps you build fault-tolerant, distributed, and asynchronous actors. If you're working on distributed systems, microservices, or real-time applications, Kameo offers a simple yet powerful API for handling concurrency, panic recovery, and remote messaging between nodes. Key Features: - Async Rust: Each actor runs as a separate Tokio task, making concurrency management simple. - Remote Messaging: Seamlessly send messages to actors across different nodes. - Supervision and Fault Tolerance: Create self-healing systems with actor…

    2024 · github.com · its alternatives →

23. 23
    Hellepoll is a blazingly-fast async HTTP server written in C++▲35

    This is based on an approach I made for a very high performance message and video multiplexing server. The project died, but I'm glad I get to share the a basic version with some http test code now. I admit this is the second time I've tried to show this off here today; I posted earlier but it got lost when no-one was watching :(

    2011 · github.com · its alternatives →

24. 24
    We packaged an MCP server inside Chromium▲46

    Hey HN, we just shipped a browser with an inbuilt MCP server! We're a YC startup (S24) building BrowserOS — an open‑source Chromium fork. We're a privacy‑first alternative to the new wave of AI browsers like Dia, Perplexity Comet. Since launching ~3 months ago, the #1 request has been to expose our browser as an MCP server. -- Google beat us to launch with chrome-devtools-mcp (solid product btw), which lets you build/debug web apps by connecting Chrome to coding assistants. But we wanted to take this a step further: we packaged the MCP server directly into our browser binary. That gives…

    2025 · github.com · its alternatives →

Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →