H2O - the optimized HTTP/2 server

H2O is a new generation HTTP server that provides quicker response to users with less CPU utilization when compared to older generation of web servers. Designed from ground-up, the server takes full advantage of HTTP/2 features including prioritized content serving and server push, promising outstanding experience to the visitors of your web site.

Explanation of the benchmark charts can be found in the benchmarks page.

Key Features

HTTP/1.0, HTTP/1.1
HTTP/2
- full support for dependency and weight-based prioritization with server-side tweaks
- cache-aware server push
TCP Fast Open
TLS
- session resumption (standalone & memcached)
- session tickets with automatic key rollover
- automatic OCSP stapling
- forward secrecy & fast AEAD ciphers¹
- private key protection using privilege separation
static file serving
FastCGI
reverse proxy
scriptable using mruby (Rack-based)
graceful restart and self-upgrade

News

Version 2.1.0 is now available (Jan 17 2017)
Version 2.0.6 is now available (Jan 5 2017)
Version 2.0.5 and 2.1.0-beta4 have been released with a vulnerability fix for CVE-2016-4864 (Dec 21 2016)

List of all the vulnerabilities having been fixed can be found here.

Notes:

chacha20-poly1305: see Do the ChaCha: better mobile performance with cryptography