lighttpd (pronounced "lighty") is an open-source

web server A web server is computer software and underlying hardware that accepts requests via HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, commonly a web browser or web crawler, initiate ...

optimized for speed-critical environments while remaining standards-compliant, secure and flexible. It was originally written by Jan Kneschke as a

proof-of-concept Proof of concept (POC or PoC), also known as proof of principle, is a realization of a certain method or idea in order to demonstrate its feasibility, or a demonstration in principle with the aim of verifying that some concept or theory has prac ...

of the

c10k problem The C10k problem is the problem of optimizing network sockets to handle a large number of clients at the same time. The name C10k is a numeronym for concurrently handling ten thousand connections. Handling many concurrent connections is a differe ...

– how to handle 10,000 connections in parallel on one server, but has gained worldwide popularity. Its name is a

portmanteau A portmanteau word, or portmanteau (, ) is a blend of words
".

Premise

The low memory footprint (compared to other web servers), small central processing unit, CPU load and speed optimizations make lighttpd suitable for servers that are suffering load problems, or for serving static media separately from dynamic content. lighttpd is

free and open-source software Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

and is distributed under the

BSD license BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lic ...

. It runs natively on

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

operating systems, as well as

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

Application support

lighttpd supports the

FastCGI FastCGI is a binary protocol for interfacing interactive programs with a web server. It is a variation on the earlier Common Gateway Interface (CGI). FastCGI's main aim is to reduce the overhead related to interfacing between web server and CGI ...

SCGI The Simple Common Gateway Interface (SCGI) is a protocol for applications to interface with HTTP servers, as an alternative to the CGI protocol. It is similar to FastCGI but is designed to be easier to parse. Unlike CGI, it permits a long-running ...

and CGI interfaces to external programs, allowing web applications written in any programming language to be used with the server. As a particularly popular language,

PHP PHP is a general-purpose scripting language geared toward web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by The PHP Group. ...

performance has received special attention. Lighttpd's FastCGI can be configured to support PHP with opcode caches (like APC) properly and efficiently. Additionally, it has received attention from its popularity within the

Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (pro ...

Perl Perl is a family of two high-level, general-purpose, interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was offici ...

Ruby A ruby is a pinkish red to blood-red colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sa ...

and

Lua Lua or LUA may refer to: Science and technology * Lua (programming language) * Latvia University of Agriculture * Last universal ancestor, in evolution Ethnicity and language * Lua people, of Laos * Lawa people, of Thailand sometimes referred t ...

communities. Lighttpd also supports

WebDNA WebDNA is a server-side scripting, interpreted language with an embedded database system, specifically designed for the World Wide Web. Its primary use is in creating database-driven dynamic web page applications. Released in 1995, the name was re ...

, the resilient

in-memory database An in-memory database (IMDB, or main memory database system (MMDB) or memory resident database) is a database management system that primarily relies on main memory for computer data storage. It is contrasted with database management systems that e ...

system designed to build database-driven websites. It is a popular web server for the

Catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

and

Ruby on Rails Ruby on Rails (simplified as Rails) is a server-side web application framework written in Ruby under the MIT License. Rails is a model–view–controller (MVC) framework, providing default structures for a database, a web service, and we ...

web frameworks. Lighttpd does not support

ISAPI The Internet Server Application Programming Interface (ISAPI) is an N-tier API of Internet Information Services (IIS), Microsoft's collection of Windows-based web server services. The most prominent application of IIS and ISAPI is Microsoft's we ...

Features

* Load balancing, CGI,

HTTP proxy The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, ...

, Servlet AJP,

WebSocket WebSocket is a computer communications protocol, providing full-duplex communication channels over a single TCP connection. The WebSocket protocol was standardized by the IETF as in 2011. The current API specification allowing web applications ...

tunnel support *

chroot 



A chroot on Unix and Unix-like operating systems is an operation that changes the apparent  root directory for the current running process and its  children. A program that is run in such a modified environment cannot name (and therefore normall ...

support * Web server event mechanism performance – select(), poll(), and epoll() * Support for more efficient event notification schemes like

kqueue 

Kqueue is a scalable event notification interface introduced in  FreeBSD 4.1 in July 2000, also supported in  NetBSD,  OpenBSD,  DragonFly BSD, and macOS. Kqueue was originally authored in 2000 by Jonathan Lemon, then involved with the FreeBSD Cor ...

and

epoll 

epoll is a  Linux kernel system call for a scalable I/O event notification mechanism, first introduced in version 2.5.44 of the  Linux kernel. Its function is to monitor multiple file descriptors to see whether I/O is possible on any of them. It i ...

* Conditional

URL rewriting In web applications, a rewrite engine is a software component that performs rewriting on URLs (Uniform Resource Locators), modifying their appearance. This modification is called URL rewriting. It is a way of implementing URL mapping or routing ...

(mod_rewrite) * TLS/SSL with

SNI SNI may refer to: Science and technology * Substitution nucleophilic internal, a chemistry reaction mechanism * Swedish Standard Industrial Classification, a Swedish economic classification system * Server Name Indication, an extension to the ...

support, via

OpenSSL OpenSSL is a software library for applications that provide secure communications over computer networks against eavesdropping or need to identify the party at the other end. It is widely used by Internet servers, including the majority of HTT ...

GnuTLS GnuTLS (, the GNU Transport Layer Security Library) is a free software implementation of the TLS, SSL and DTLS protocols. It offers an application programming interface (API) for applications to enable secure communication over the network trans ...

Mbed TLS Mbed TLS (previously PolarSSL) is an implementation of the TLS and SSL protocols and the respective cryptographic algorithms and support code required. It is distributed under the Apache License version 2.0. Stated on the website is that Mbed ...

, NSS,

WolfSSL wolfSSL is a small, portable, embedded SSL/TLS library targeted for use by embedded systems developers. It is an open source implementation of TLS (SSL 3.0, TLS 1.0, 1.1, 1.2, 1.3, and DTLS 1.0, 1.2, and 1.3) written in the C programming lan ...

. * Authentication against an

LDAP The Lightweight Directory Access Protocol (LDAP ) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services over an Internet Protocol (IP) network. Directory servi ...

or DBI server *

RRDtool RRDtool (''round-robin database tool'') aims to handle time series data such as network bandwidth, temperatures or CPU load. The data is stored in a circular buffer based database, thus the system storage footprint remains constant over time. ...

statistics * Rule-based downloading with possibility of a script handling only authentication *

Server Side Includes Server Side Includes (SSI) is a simple interpreted server-side scripting language used almost exclusively for the World Wide Web. It is most useful for including the contents of one or more files into a web page on a web server (see below), using i ...

support (but not server-side CGI from SSI) * Flexible

virtual hosting Virtual hosting is a method for hosting multiple domain names (with separate handling of each name) on a single server (or pool of servers). This allows one server to share its resources, such as memory and processor cycles, without requiring all ...

* Modules support *

Lua programming language Lua ( ; from meaning ''moon'') is a lightweight, high-level, multi-paradigm programming language designed primarily for embedded use in applications. Lua is cross-platform, since the interpreter of compiled bytecode is written in ANSI C, ...

scripts via mod_magnet *

WebDAV WebDAV (Web Distributed Authoring and Versioning) is a set of extensions to the Hypertext Transfer Protocol (HTTP), which allows user agents to collaboratively author contents ''directly'' in an HTTP web server by providing facilities for concu ...

support *

HTTP compression HTTP compression is a capability that can be built into web servers and web clients to improve transfer speed and bandwidth utilization. HTTP data is compressed before it is sent from the server: compliant browsers will announce what methods are ...

using mod_deflate (zlib, brotli, zstd) * Light-weight (less than 1 MB) * Single-process design with only several threads. No processes or threads started per connection. *

HTTP/2 HTTP/2 (originally named HTTP/2.0) is a major revision of the HTTP network protocol used by the World Wide Web. It was derived from the earlier experimental SPDY protocol, originally developed by Google. HTTP/2 was developed by the HTTP Working ...

support since lighttpd 1.4.56 *

support since lighttpd 1.4.65

Limitations

* Versions below 1.4.40 do not officially support sending large files from CGI, FastCGI, or proxies unless X-Sendfile is used. This limitation has been removed in lighttpd 1.4.40. * No

HTTP/3 HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web, complementing the widely-deployed HTTP/1.1 and HTTP/2. Unlike previous versions which relied on the well-established TCP ( ...

support

Usage

Lighttpd was used in the past by several high-traffic websites, including

Bloglines Bloglines was a web-based news aggregator for reading syndicated feeds using the RSS and Atom formats. Users could subscribe to the syndicated feeds for free using a web browser. Bloglines offered an application programming interface that mainta ...

xkcd ''xkcd'', sometimes styled ''XKCD'', is a webcomic created in 2005 by American author Randall Munroe. The comic's tagline describes it as "a webcomic of romance, sarcasm, math, and language". Munroe states on the comic's website that the name ...

Meebo Meebo (often stylized as meebo) was an instant messaging and social networking service provider. It was founded in September 2005 by Sandy Jen, Seth Sternberg, and Elaine Wherry, and was based in Mountain View, California. Initially the company o ...

, and

YouTube YouTube is a global online video platform, online video sharing and social media, social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by ...

. The

Wikimedia Foundation The Wikimedia Foundation, Inc., or Wikimedia for short and abbreviated as WMF, is an American 501(c)(3) nonprofit organization headquartered in San Francisco, California and registered as a charitable foundation under local laws. Best kno ...

also once ran Lighttpd servers.

References

External links

* {{Web server software Cross-platform free software Free software programmed in C Free web server software Unix network-related software Web server software for Linux Windows Internet software