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H2O

A fast web server for HTTP/1.x, HTTP/2, and HTTP/3 (experimental), written in C.

GitHub Download tag-no-more-releases
Stars
11.6k
Forks
888
Licence
MIT
Language
C
Last update
4 days ago
Type
App

What it is

H2O is an HTTP server, the kind of software that delivers web pages and API responses to browsers and other clients. The README describes it as a newer-generation server that is fast and responds quickly to end users. It is written in C and can also be used as a library inside other programs.

  • Serve static websites or files over HTTP/1.x and HTTP/2
  • Test or evaluate HTTP/2 and HTTP/3 behavior with a server that supports them
  • Embed an HTTP server inside a C application, since the README says it can be used as a library

Great for

  • Teams who want a web server focused on speed and modern HTTP protocols
  • Developers who want to embed an HTTP server as a library in a C project
  • Operators comfortable with compiling and configuring server software themselves

Not ideal for

  • Beginners who want a point-and-click setup, since the README gives no simple installer or binaries
  • Teams that need HTTP/3 in production, since the README marks it as experimental
  • Projects that need a well-documented ecosystem of plugins, which the README does not describe
Step-by-step guide: how to use H2OInstall, first run, examples, tips and FAQs

How to get it

  1. 1

    Clone and build from source

    Clone the repository

    git clone https://github.com/h2o/h2o
  2. 2

    Run it

    • Clone the repository from GitHub
    • Read the build instructions in the project's documentation at h2o.examp1e.net
    • Build the server from source
    • Start the server with a configuration file as described in the documentation
  3. 3

    Get the most out of it

    • Use the library form if you want to embed HTTP serving in a C program
    • Check the documentation site for configuration options, since the README points there
    • Review SECURITY.md before deploying, and report issues through the listed address

Downloads

Source code (.zip)master branch · straight from GitHubRelease tag-no-more-releasesRelease notes and sourceOfficial website & docsh2o.examp1e.net

Strengths

  • The README describes it as very fast and focused on quick responses to end users
  • Supports HTTP/1.x, HTTP/2, and HTTP/3 in one server
  • Released under the permissive MIT License, and actively maintained with a recent push

Trade-offs

  • HTTP/3 support is labeled experimental in the README
  • The latest release has no downloadable binaries, so you will likely need to build it yourself
  • Detailed usage and configuration live on an external documentation site that was not included in the README text

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.