View source for Lighttpd

{{Short description|Web server}}
{{lowercase|title=lighttpd}}
{{Infobox software
| name                   = lighttpd
| title                  = lighttpd
| logo                   = Lighttpd logo.svg
| screenshot             = 
| screenshot size        = 
| caption                = 
| collapsible            = 
| author                 = [[Jan Kneschke]]
| released               = {{Start date and age|2003|03}}
| latest release version = {{wikidata|property|preferred|references|edit|Q217765|P348|P548=Q2804309}}
| latest release date    = {{start date and age|{{wikidata|qualifier|preferred|single|Q217765|P348|P548=Q2804309|P577}}}}
| latest preview version = 
| latest preview date    = 
| programming language   = [[C (programming language)|C]]
| language               = English
| genre                  = [[Web server]]
| license                = [[BSD licenses|BSD-3-Clause]]
}}

'''lighttpd''' (prescribed pronunciation: "lighty")<ref>{{cite web|url=http://www.lighttpd.net/|title=lighttpd fly light|access-date=2010-06-13|quote=all of these describe lighttpd (pron. lighty)}}.</ref> is an open-source [[web server]] optimized for speed-critical environments while remaining standards-compliant, secure and flexible.{{Citation needed|date=April 2010}} It was originally written by Jan Kneschke as a [[proof-of-concept]] of the [[c10k problem]] – how to handle 10,000 connections in parallel on one server,<ref>
{{Cite web| url=http://www.lighttpd.net/story| title=lighttpd: Story| access-date=22 December 2008| publisher=lighttpd.net}}</ref>
but has gained worldwide popularity.<ref>{{Cite web| url=http://trac.lighttpd.net/trac/wiki/PoweredByLighttpd| title=Powered By lighttpd| access-date=22 December 2008| publisher=Lighttpd wiki}}</ref> Its name is a [[portmanteau]] of "light" and "[[httpd]]".

==Premise==
The low memory footprint (compared to other web servers),<ref>{{cite web| url=http://wiki.dreamhost.com/Web_Server_Performance_Comparison| title=Web Server Performance Comparison| access-date=15 March 2012| archive-url=https://web.archive.org/web/20160605174449/http://wiki.dreamhost.com/Web_Server_Performance_Comparison| archive-date=5 June 2016| url-status=dead}}.</ref> small [[central processing unit|CPU]] load and speed optimizations<ref>Gabriel Kerneis and Juliusz Chroboczek. [http://www.pps.jussieu.fr/~jch/research/cpc-bench.pdf ''Are events fast?'']. PPS technical report, University of Paris 7. 2009.</ref>  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]] and is distributed under the [[BSD license]]. It runs natively on [[Unix-like]] operating systems, with experimental support for [[Microsoft Windows]].<ref>{{cite web |url=https://redmine.lighttpd.net/projects/lighttpd/wiki/Release-1_4_70|title=lighttpd release 1.4.70|access-date=2023-05-10}}</ref>

==Application support==
lighttpd supports the [[FastCGI]], [[Simple Common Gateway Interface|SCGI]] and [[Common Gateway Interface|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]] performance has received special attention. Lighttpd's FastCGI can be configured to support PHP with [[PHP accelerator|opcode caches]] (like [[Alternative PHP Cache|APC]]) properly and efficiently. Additionally, it has received attention from its popularity within the [[Python (programming language)|Python]], [[Perl]], [[Ruby (programming language)|Ruby]] and [[Lua (programming language)|Lua]] communities. Lighttpd also supports WebDNA, the resilient [[in-memory database]] system designed to build database-driven websites. It is a popular web server for the [[Catalyst (software)|Catalyst]] and [[Ruby on Rails]] web frameworks. Lighttpd does not support [[Internet Server Application Programming Interface|ISAPI]].

==Features==
* [[Load balancing (computing)|Load balancing]], [[Common_Gateway_Interface|CGI]], [[FastCGI]], [[Simple Common Gateway Interface|SCGI]], [[HTTP proxy]], Servlet [[Apache_JServ_Protocol|AJP]], [[WebSocket]] tunnel support
* <code>[[chroot]]</code> support
* Web server event mechanism performance – <code>select()</code>, <code>poll()</code>, and <code>epoll()</code><ref>{{cite web |title= Comparing and Evaluating epoll, select, and poll Event Mechanisms |first1= Louay |last1= Gammo |first2= Tim |last2= Brecht |first3= Amol |last3= Shukla |first4= David |last4= Pariag |publisher= University of Waterloo |work= Linux Symposium |date= 2004 |volume= 1 |page= 215 |url=https://cs.uwaterloo.ca/~brecht/papers/ols-2004.pdf }}</ref>
* Support for more efficient [[event notification]] schemes like <code>[[kqueue]]</code> and <code>[[epoll]]</code>
* Conditional [[URL rewriting]] (mod_rewrite)
* [[Transport Layer Security|TLS/SSL]] with [[Server Name Indication|SNI]] support, via [[OpenSSL]], [[GnuTLS]], [[Mbed TLS]], [[Network_Security_Services|NSS]], [[WolfSSL]].<ref>{{cite web |author1=gstrauss |title=1.4.56 - Lighttpd - fly light |url=https://www.lighttpd.net/2020/11/29/1.4.56/ |website=Lighttpd |access-date=2023-06-02 |date=2020-11-29}}</ref>
* Authentication against an [[Lightweight Directory Access Protocol|LDAP]] or DBI server
* [[RRDtool]] statistics
* Rule-based downloading with possibility of a script handling only authentication
* [[Server Side Includes]] support (but not server-side CGI from SSI)<ref>[http://redmine.lighttpd.net/issues/show/1101 Lighttpd - Bug #1101: SSI include virtual does not run cgi] – lighty labs</ref>
* Flexible [[virtual hosting]]
* Modules support
* [[Lua (programming language)|Lua programming language]] scripts via mod_magnet<ref>{{Cite web|url=http://redmine.lighttpd.net/projects/lighttpd/wiki/Docs:ModMagnet|title = Docs ModMagnet - Lighttpd - lighty labs}}</ref> 
* [[WebDAV]] support
* [[HTTP compression]] using mod_deflate (zlib, brotli, zstd)
* Light-weight (less than 1 [[Megabyte|MB]])<ref>
{{Cite web| url=http://download.lighttpd.net/lighttpd/| title=lighttpd releases| access-date=20 June 2010| publisher=lighttpd.net}}</ref>
* Single-process design with only several threads. No processes or threads started per connection.
* [[HTTP/2]] support since lighttpd 1.4.56
* [[HTTP/2]] [[WebSocket]] support since lighttpd 1.4.65
* [[Server_Name_Indication#Encrypted_Client_Hello|TLS Encrypted Client Hello (ECH)]]  support since lighttpd 1.4.77<ref>{{Cite web|url=http://wiki.lighttpd.net/TLS_ECH|title = lighttpd TLS ECH}}</ref>

==Limitations==
* Versions below 1.4.40 do not officially support sending large files from CGI, FastCGI, or proxies<ref>{{cite web|url =http://redmine.lighttpd.net/issues/1283|title = Memory usage increases when proxy+ssl+large file|publisher=lighttpd bug tracker|access-date= 2011-04-11}}</ref> unless X-Sendfile is used.  This limitation has been removed in lighttpd 1.4.40.<ref>{{cite web|url =https://redmine.lighttpd.net/issues/933|title = lighty should buffer responses (after it grows above certain size) on disk|publisher=lighttpd bug tracker|access-date= 2016-07-16}}</ref>
* No [[HTTP/3]] support

==Usage==
Lighttpd was used in the past by several high-traffic websites, including [[Bloglines]], [[xkcd]], [[Meebo]], and [[YouTube]].<ref>{{cite web|url = http://www.serverwatch.com/stypes/servers/article.php/17191_3678346|title = Fly Light With Lighttpd Web Server| publisher = ServerWatch | access-date = 2008-02-12|archive-url=https://web.archive.org/web/20140331045948/http://www.serverwatch.com/stypes/servers/article.php/17191_3678346|archive-date=31 March 2014}}</ref>{{better ref needed|date=July 2015}} The [[Wikimedia Foundation]] also once ran Lighttpd servers.<ref>{{cite web
| url=http://www.lighttpd.net/2007/4/4/powered-by-lighttpd
| title=Powered by Lighttpd
| publisher=The official site
| date=2007-04-04
| quote=lighttpd is used by many well-known sites. The typical scenario is using lighttpd as off-load server to push out static content and leave the complex work to another server.
| access-date=2008-12-22}}</ref>
Due to relatively small size it's often used in embedded devices like GL.iNet and [[Turris Omnia]].

It's also used by [[git]] as a HTTP server daemon.

==See also==<!-- PLEASE RESPECT ALPHABETICAL ORDER -->
{{Portal|Free and open-source software}}
* [[Comparison of web server software]]
* [[Internet Cache Protocol]]
* [[Proxy server]] which discusses client-side proxies
* [[Reverse proxy]] which discusses origin-side proxies
* [[Traffic Server]]
* [[Web accelerator]] which discusses host-based HTTP acceleration

==References==
{{Reflist}}

==Further reading==
{{refbegin}}
* {{cite book
| first1      = Andre
| last1       = Bogus
| date        = October 29, 2008
| title       = Lighttpd
| publisher   = [[Packt Publishing]]
| edition     = 1st
| page        = 236
| isbn        = 978-1847192103
| url         = https://www.packtpub.com/lighttpd/book
}}
{{refend}}

==External links==
* {{Official website}}

{{Web server software}}

[[Category:Cross-platform free software]]
[[Category:Free software programmed in C]]
[[Category:Free web server software]]
[[Category:Unix network-related software]]
[[Category:Web server software for Linux]]
[[Category:Windows Internet software]]