Overview

__Basic HTTP features:__


 * handling of static files, index files, and autoindexing;
 * accelerated reverse proxying (without caching), simple load balancing and fault tolerance;
 * FastCGI, with simple load balancing and fault tolerance;
 * modular architecture. Filters include gzipping, byte ranges, chunked responses, and SSI-filter. In the SSI filter, multiple subrequests to a proxy or FastCGI are handled in parallel;
 * SSL and TLS SNI support;

__IMAP/POP3 proxy server features:__


 * user redirection to IMAP/POP3 backend using an external HTTP authentication server;
 * User authentication using an external HTTP authentication server and connection redirection to internal SMTP backend;
 * Authentication methods:
 * POP3: POP3 USER/PASS, APOP, AUTH LOGIN PLAIN CRAM-MD5;
 * IMAP: IMAP LOGIN;
 * SMTP: AUTH LOGIN PLAIN CRAM-MD5;
 * SSL support;
 * STARTTLS and STLS support in the IMAP and POP3 mode;

__Supported Operating Systems:__


 * FreeBSD 3.x, 4.x, 5.x, 6.x i386; FreeBSD 5.x, 6.x amd64;
 * Linux 2.2, 2.4, 2.6 i386; Linux 2.6 amd64;
 * Solaris 8 i386; Solaris 9 i386 and sun4u; Solaris 10 i386;
 * MacOS X (10.4) PPC;

__Architecture and scalability:__


 * one master process and several worker processes. The workers are single-threaded and run under an unpriviliged user
 * kqueue (FreeBSD 4.1+), epoll (Linux 2.6+), rt signals (Linux 2.2.19+), /dev/poll (Solaris 7 11/99+), select, and poll support;
 * various kqueue features support including EV_CLEAR, EV_DISABLE (to disable event temporalily), NOTE_LOWAT, EV_EOF, number of available data, the error codes;
 * sendfile (FreeBSD 3.1+), sendfile (Linux 2.2+), sendfile64 (Linux 2.4.21+), and sendfilev (Solaris 8 7/01+) support;
 * accept-filter (FreeBSD 4.1+) and TCP_DEFER_ACCEPT (Linux 2.4+) support;
 * 10,000 inactive HTTP keep-alive connections take about 2.5M memory.
 * minimizes data copy operations;

__Other HTTP features:__


 * name- and IP-based virtual servers;
 * a GET interface to Memcached;
 * support for keep-alive and pipelined connections;
 * flexible and easy configuration;
 * reconfiguration and online upgrade without interruption of the client processing;
 * custom access log formats, buffered writing, and quick log rotation;
 * 4xx-5xx error codes redirection;
 * PCRE-based rewrite module;
 * access control based on client IP address and HTTP Basic authentication;
 * PUT, DELETE, and MKCOL methods;
 * support for FLV (Flash video);
 * bandwidth throttling

__Experimental features:__


 * embdedded
 * An experimental module, which works with sockets through /, only under FreeBSD.
 * Experimental support for threads, FreeBSD 4.x implementation based on rfork

The main English Nginx site is http://sysoev.ru/en/

The draft English documentation by Aleksandar Lazic is here.