Metalink - AbsoluteAstronomy.com

Metalink is a cross-platform and cross-application Internet standard

Internet standard

In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force .-Overview:...

/framework/file format for programs that download, including download manager

Download manager

A download manager is a computer program dedicated to the task of downloading possibly unrelated stand-alone files from the Internet for storage...

s, BitTorrent

BitTorrent client

BitTorrent is a peer-to-peer program developed by Bram Cohen and BitTorrent, Inc. used for uploading and downloading files via the BitTorrent protocol. BitTorrent was the first client written for the protocol. It is often nicknamed Mainline by developers denoting its official origins. Since version...

clients, Web browsers, FTP clients, and P2P

Peer-to-peer

Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads among peers. Peers are equally privileged, equipotent participants in the application...

programs. For increased convenience, the multiple download locations for a file (FTP

File Transfer Protocol

File Transfer Protocol is a standard network protocol used to transfer files from one host to another host over a TCP-based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server...

/HTTP

Hypertext Transfer Protocol

The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....

/P2P

Peer-to-peer

) and other metadata

Metadata

The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...

in HTTP header fields and/or an XML

Extensible Markup Language

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

file with the extension .meta4 or .metalink. The duplicate download locations provide reliability in case one method fails. Some clients also achieve faster download speeds by allowing different chunks/segments of each file to be downloaded from multiple resources at the same time (segmented downloading

Segmented downloading

Segmented downloading can be a more efficient way of downloading files from many peers at once. The one single file is downloaded, in parallel, from several distinct sources or uploaders of the file...

).

Other features include automatic hash verification of finished downloads, automatic repair of downloads with errors, listing multiple files to be added to a download queue, and automatic OS/language selection.

Metalink is extensible, and supports listing multiple partial and full file hashes

Cryptographic hash function

A cryptographic hash function is a deterministic procedure that takes an arbitrary block of data and returns a fixed-size bit string, the hash value, such that an accidental or intentional change to the data will change the hash value...

along with PGP

Pretty Good Privacy

Pretty Good Privacy is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting and decrypting texts, E-mails, files, directories and whole disk partitions to increase the security...

signatures. Most clients only support verifying MD5

MD5

The MD5 Message-Digest Algorithm is a widely used cryptographic hash function that produces a 128-bit hash value. Specified in RFC 1321, MD5 has been employed in a wide variety of security applications, and is also commonly used to check data integrity...

, SHA-1, & SHA-256, however. Besides FTP and HTTP mirror

Mirror (computing)

In computing, a mirror is an exact copy of a data set. On the Internet, a mirror site is an exact copy of another Internet site.Mirror sites are most commonly used to provide multiple sources of the same information, and are of particular value as a way of providing reliable access to large downloads...

locations and rsync

Rsync

rsync is a software application and network protocol for Unix-like and Windows systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important feature of rsync not found in most similar...

, it also supports listing the P2P methods BitTorrent, ed2k, magnet link or any other that uses a URI

Uniform Resource Identifier

In computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...

Development History

Metalink 3.0 was publicly released in 2005. It was designed to aid in downloading Linux ISO image

ISO image

An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...

s and other large files on release day, when servers would be overloaded (each server would have to be tried manually) and to repair large downloads by replacing only the parts with errors instead of fully re-downloading them. It was initially adopted by download manager

Download manager

A download manager is a computer program dedicated to the task of downloading possibly unrelated stand-alone files from the Internet for storage...

s, and was used by open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

projects such as OpenOffice.org

OpenOffice.org

OpenOffice.org, commonly known as OOo or OpenOffice, is an open-source application suite whose main components are for word processing, spreadsheets, presentations, graphics, and databases. OpenOffice is available for a number of different computer operating systems, is distributed as free software...

and Linux distribution

Linux distribution

A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

s. A community developed around it, more download programs supported it (including proprietary ones) and it saw commercial adoption. In 2008, the community took their work to the Internet Engineering Task Force

Internet Engineering Task Force

The Internet Engineering Task Force develops and promotes Internet standards, cooperating closely with the W3C and ISO/IEC standards bodies and dealing in particular with standards of the TCP/IP and Internet protocol suite...

which resulted in Metalink 4.0 in 2010, described in a Standards Track RFC

Request for Comments

In computer network engineering, a Request for Comments is a memorandum published by the Internet Engineering Task Force describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems.Through the Internet Society, engineers and...

. Metalink 3.0 (with the extension .metalink) and Metalink 4.0 (with the extension .meta4) are incompatible because they have a slightly different format. In 2011, another Standards Track RFC

Request for Comments

described Metalink in HTTP header fields.

Client programs

aria2 (GPL) is a Unix/Windows command line download utility that supports BitTorrent and Metalink (HTTP/FTP/BitTorrent)
DownThemAll (GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

), a Firefox extension and download manager that has basic Metalink support.
FlashGot
FlashGot
FlashGot is a free and open source Mozilla extension meant to handle single and massive downloads with several external download managers.-Metalink support:...

(GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

), a Firefox extension for integrating with many Download Managers, supports Metalink.
Free Download Manager
Free Download Manager
Free Download Manager is a free open source graphical download manager for the Microsoft Windows operating system.FDM was previously proprietary software, but with the release of version 2.5 it has been open source. Starting with version 3.0.850 , source code is no longer provided as a packaged...

(GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

), a Windows Download Manager, supports Metalink (HTTP/FTP) in version 2.5.
GetRight
GetRight
GetRight is a shareware download manager developed by Headlight Software.-Features:GetRight is able to pause and resume downloads, download from multiple servers to speed up download time , scheduling the starting and stopping of downloads and shutting off the computer or disconnecting the modem...

6, a Windows Download Manager, supports Metalink (HTTP/FTP/BitTorrent).
jDownloader
JDownloader
JDownloader is a download manager, written in Java, which allows the automatic downloading of files and split files from one-click hosting sites such as Rapidshare and Megaupload. JDownloader supports the use of premium accounts. Certain parts of JDownloader are open source.JDownloader is better...

is an open source download manager written in Java.
KGet
KGet
KGet is a free download manager for KDE. By default it is the download manager used for Konqueror, but can also be used with Mozilla Firefox. KGet is part of the KDE Network package, and was featured by Tux Magazine and Free Software Magazine.-History:...

(GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

), KDE
KDE
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

's native download manager, supports Metalink in KDE 4.
Net Transport
Net Transport
Net Transport is a shareware download manager and stream ripper for Windows made by Xi Software.The company also develops FTP Transport, which is included with Net Transport.-External links:** from *...

, a Windows Download Manager, supports Metalink.
Orbit Downloader
Orbit Downloader
-External links:* * at Download.com* at Softonic.com...

, a Windows Download Manager, supports Metalink (HTTP/FTP).
Phex
Phex
- External links :* * * * at SourceForge.net* at *...

(GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

), a Mac/Unix/Windows gnutella
Gnutella
Gnutella is a large peer-to-peer network which, at the time of its creation, was the first decentralized peer-to-peer network of its kind, leading to other, later networks adopting the model...

client, supports Metalink downloads along with exporting a library to Metalink for sharing between users.
Retriever is a closed source cross platform Java download manager that supports Metalink and BitTorrent.
SmartFTP
SmartFTP
SmartFTP is an FTP/FTPS/SFTP client for Windows, developed by SmartSoft Ltd. Features include SSL/TLS, IPv6 and FXP support, a backup tool, a transfer queue, proxy and firewall support, multiple connections, chmod features, Drag-and-drop and localization for over 20 languages, including English,...

, a Windows GUI FTP client, supports Metalink for adding files to an FTP transfer queue and hash verification.
VeryCD
VeryCD
VeryCD is a Chinese website that shares files via eD2k links. The website began in September 2003 by Huang Yimeng . In June 2005, Shanghai Source Networking Technology Co., Ltd was established. It is a for-profit organization headquartered in Shanghai, China...

's easyMule (version 1 is GPLed
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

, ver.2 may be GPL-Violation) is a version of eMule
EMule
eMule is a free peer-to-peer file sharing application for Microsoft Windows. Started in May 2002 as an alternative to eDonkey2000, eMule now connects to both the eDonkey network and the Kad network...

with Metalink support.
wxDownload Fast
WxDownload Fast
wxDownload Fast is a free/open source download manager. It was created to be multi-platform, so at the moment it builds on Windows , Linux, BSD, and Mac OS X....

(GPL) is a Mac/Unix/Windows download manager that supports Metalink (HTTP/FTP).
yum
Yellow dog Updater, Modified
The Yellowdog Updater, Modified is an open-source command-line package-management utility for RPM-compatible Linux operating systems and has been released under the GNU General Public License. It was developed by Seth Vidal and a group of volunteer programmers...

, an open source command line package management
Package management system
In software, a package management system, also called package manager, is a collection of software tools to automate the process of installing, upgrading, configuring, and removing software packages for a computer's operating system in a consistent manner...

utility for RPM
RPM Package Manager
RPM Package Manager is a package management system. The name RPM variously refers to the .rpm file format, files in this format, software packaged in such files, and the package manager itself...

-compatible Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

s, uses Metalink internally, invisible to the user.
ZYpp
ZYpp
ZYpp is a package management engine that powers Linux applications like YaST, Zypper and the openSUSE/SUSE Linux Enterprise implementation of PackageKit. Unlike other common package managers, it provides a powerful satisfiability solver to compute package dependencies and a convenient package...

, the package management engine that powers YaST2 and Zypper, supports Metalink for downloading. It uses aria2 internally.

In use

Mandriva Linux

Mandriva Linux is a Linux distribution distributed by Mandriva. It uses the RPM Package Manager...

has integrated Metalink into package management with urpmi

Urpmi

urpmi is a Mandriva Linux package management tool for installing, removing, updating and querying software packages of local or remote media. It wraps around the package manager rpm with the aim that the user should not have to suffer the often-encountered dependency hell...

and aria2.
Fedora

Fedora (operating system)

Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...

has integrated Metalink into package management with yum

Yellow dog Updater, Modified

The Yellowdog Updater, Modified is an open-source command-line package-management utility for RPM-compatible Linux operating systems and has been released under the GNU General Public License. It was developed by Seth Vidal and a group of volunteer programmers...

. openSUSE

OpenSUSE

openSUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported openSUSE Project and sponsored by SUSE...

has integrated Metalink into package management with ZYpp

ZYpp

ZYpp is a package management engine that powers Linux applications like YaST, Zypper and the openSUSE/SUSE Linux Enterprise implementation of PackageKit. Unlike other common package managers, it provides a powerful satisfiability solver to compute package dependencies and a convenient package...

and aria2.

Wubi, the Windows-based Ubuntu

Ubuntu (operating system)

Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

installer, uses Metadl (LGPL) to download Ubuntu ISO image

ISO image

An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...

s and takes advantage of Metalink's features of higher availability and increased reliability. If there are errors in the download, they are repaired, instead of restarting the large download.

Appupdater (GPL

GNU General Public License

The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

) for Windows "is similar to apt-get or yum on Linux. It automates the process of installing and maintaining up to date versions of programs."

Currently, OpenOffice.org

OpenOffice.org

uses Metalinks to distribute their free office suite. cURL

CURL

cURL is a computer software project providing a library and command-line tool for transferring data using various protocols. The cURL project produces two products, libcurl and cURL...

offers Metalinks of their downloads. UniProt

UniProt

UniProt is a comprehensive, high-quality and freely accessible database of protein sequence and functional information, many of which are derived from genome sequencing projects...

Consortium also provides a Metalink for their large protein database. Dofus

Dofus

Dofus is a Flash based massively multiplayer online role-playing game developed and published by Ankama Games, a French computer game manufacturer. Originally released solely in French, it has since been translated into many other languages. It is primarily a Pay to Play game, though it still...

, a Flash MMORPG

MMORPG

Massively multiplayer online role-playing game is a genre of role-playing video games in which a very large number of players interact with one another within a virtual game world....

uses Metalinks for downloads and so does Sage, the open-source mathematical software.

The software hosting and collaboration platform Origo generates Metalinks for all hosted releases.

The following Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

distributions use Metalink for ISO image

ISO image

An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...

distribution: 64 Studio, Adios

Adios

Adiós may refer to:*Adios , a champion harness racing sire*Adiós, Navarre*Automatic Distillation of Structure , an algorithm that can teach itself grammar by analyzing text*A pair of Adio skate shoes, or other apparel made by the company...

, Bayanihan Linux, BeleniX

BeleniX

BeleniX is an operating system distribution built using the OpenSolaris source base. It can be used as a Live CD as well as installed to hard disk. From the information provided on the BeleniX website, it may appear that currently, BeleniX is compiled only for 32-bit execution...

, Berry Linux

Berry Linux

Berry Linux is a Live CD Linux distribution that has English and Japanese support. Berry Linux is based on and is compatible with Fedora 15 packages. The distribution is primarily focused on use as a Live CD, but it can also be installed to a live USB drive...

, BLAG Linux and GNU

BLAG Linux and GNU

BLAG Linux and GNU is a GNU/Linux distribution made by the Brixton Linux Action Group.BLAG is a single-CD distro with applications desktop users "expect" from a desktop including multimedia, graphics, desktop internet applications and more. BLAG also includes a collection of server packages...

, Bluewhite64 Linux, Damn Small Linux

Damn Small Linux

Damn Small Linux or DSL is a computer operating system for the x86 family of personal computers. It is free and open source software under the terms of GNU GPL and other free and open source licenses. It was designed to run graphical applications on older PC hardware—for example, machines with...

, Fedora

Fedora (operating system)

Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...

, GoboLinux

GoboLinux

GoboLinux is a free and open source operating system whose most prominent feature is a reorganization of the traditional Linux file system. Rather than following the Filesystem Hierarchy Standard like most Unix-like systems, each program in a GoboLinux system has its own subdirectory tree, where...

, Granular Linux

Granular Linux

Granular, or Granular Linux, is a Linux distribution targeted at the common desktop users. Granular is based on PCLinuxOS and comes as an installable live CD. The CD version of Granular features two desktop environments - KDE and a development version of Enlightenment...

, KateOS, Linux Mint

Linux Mint

Linux Mint is a Linux-based computer operating system best known for its usability and ease of installation, particularly for users with no previous GNU/Linux experience...

, openSUSE

OpenSUSE

openSUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported openSUSE Project and sponsored by SUSE...

, Pardus Linux

Pardus (operating system)

Pardus is a Linux distribution developed with support from the Turkish government. Pardus’ main focus is office-related work, including the use in Turkish government agencies. Despite that, Pardus ships in several languages. Its ease of use and availability free of charge spawned numerous...

, PCLinuxOS

PCLinuxOS

PCLinuxOS, often shortened to PCLOS, is a GNU/Linux distribution, with KDE Plasma Desktop as its default user interface. It is a primarily free software operating system for personal computers aimed at ease of use...

, PuppyLinux, Sabayon Linux, StartCom Enterprise Linux, SUSE Linux, Ubuntu

Ubuntu (operating system)

Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...

.

The following FreeBSD

FreeBSD

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

based distributions use Metalink for ISO image

ISO image

An ISO image is an archive file of an optical disc, composed of the data contents of every written sector of an optical disc, including the optical disc file system...

distribution: DesktopBSD

DesktopBSD

DesktopBSD is a Unix-derivative, desktop-oriented operating system based on FreeBSD. Its goal is to combine the stability of FreeBSD with the ease-of-use of KDE, which is the default graphical user interface.- History and development :...

, MidnightBSD

MidnightBSD

MidnightBSD is a free Unix-like, desktop-oriented operating system based on FreeBSD 6.1. It borrows heavily from the NEXTSTEP graphical user interface.- History and development :...

, PC-BSD

PC-BSD

PC-BSD is a Unix-like, desktop-oriented operating system based on FreeBSD. It aims to be easy to install by using a graphical installation program, and easy and ready-to-use immediately by providing KDE SC as the pre-installed graphical user interface. PC-BSD provides official binary nVidia and...

and TrueBSD.

File based search engine findthatfile provides search for Metalinks.

Metalink client feature comparison

A guide to which clients support which Metalink features:

	aria2	DownThemAll	Free Download Manager Free Download Manager Free Download Manager is a free open source graphical download manager for the Microsoft Windows operating system.FDM was previously proprietary software, but with the release of version 2.5 it has been open source. Starting with version 3.0.850 , source code is no longer provided as a packaged...	GetRight GetRight GetRight is a shareware download manager developed by Headlight Software.-Features:GetRight is able to pause and resume downloads, download from multiple servers to speed up download time , scheduling the starting and stopping of downloads and shutting off the computer or disconnecting the modem...	KGet KGet KGet is a free download manager for KDE. By default it is the download manager used for Konqueror, but can also be used with Mozilla Firefox. KGet is part of the KDE Network package, and was featured by Tux Magazine and Free Software Magazine.-History:...	Metadl	Metalink Checker	Orbit Downloader Orbit Downloader -External links:* * at Download.com* at Softonic.com...	Phex Phex - External links :* * * * at SourceForge.net* at *...	Retriever	SmartFTP SmartFTP SmartFTP is an FTP/FTPS/SFTP client for Windows, developed by SmartSoft Ltd. Features include SSL/TLS, IPv6 and FXP support, a backup tool, a transfer queue, proxy and firewall support, multiple connections, chmod features, Drag-and-drop and localization for over 20 languages, including English,...	Speed Download	TheWorld	wxDownload Fast WxDownload Fast wxDownload Fast is a free/open source download manager. It was created to be multi-platform, so at the moment it builds on Windows , Linux, BSD, and Mac OS X....
License Software licensing A software license is a legal instrument governing the usage or redistribution of software. All software is copyright protected, except material in the public domain. Contractual confidentiality is another way of protecting software...	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )	Proprietary / $29.95 for Standard, $49.95 for Pro	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU Lesser General Public License GNU Lesser General Public License The GNU Lesser General Public License or LGPL is a free software license published by the Free Software Foundation . It was designed as a compromise between the strong-copyleft GNU General Public License or GPL and permissive licenses such as the BSD licenses and the MIT License... )	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )	Proprietary / Freeware Freeware Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )	Proprietary / Freeware Freeware Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...	Proprietary / Freeware Freeware Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the... for personal, $36.95 commercial	Proprietary / $25	Proprietary / Freeware Freeware Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...	Free Software Free software Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do... (GNU General Public License GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project.... )
Interface	CLI, XML-RPC XML-RPC XML-RPC is a remote procedure call protocol which uses XML to encode its calls and HTTP as a transport mechanism. "XML-RPC" also refers generically to the use of XML for remote procedure call, independently of the specific protocol...	GUI	GUI	GUI	GUI	GUI	CLI	GUI	GUI	GUI	GUI	GUI	GUI	GUI
Metalink 4.0
Runs on Linux Linux Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
Runs on Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
Runs on Mac OS X Mac OS X Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
Resume Downloads
Segmented Downloads
Multiple File support
"location"
OS
Language
HTTP with Transparent Negotiation
HTTP
FTP
BitTorrent
magnet
MD5 Hashes									?
SHA-1 Hashes
SHA-256 Hashes
Piece Hashes
PGP Signatures

No clients support rsync

Rsync

at this time.

Metalink generation

Metalink is XML so they can be hand crafted or XML tools can be used for automation. These tools are specifically for Metalink.

Bouncer is "database driven mirror management app that has three main components - a bounce script, a sentry script to check mirrors and files for integrity and a set of web-based administration tools." Bouncer supports Metalink via a patch that has not yet been integrated upstream.
Geo McFly (GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

) is an on the fly generator of metalinks based on the downloader's geographical location, written in Python
Python (programming language)
Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...

.
Metalink Editor (GPL) is a Cross Platform GUI Metalink editor written in Python which allows you to create and edit Metalinks.
Metalink Library (GPL) is a Cross Platform Metalink library for Python and PHP based on Metalink Editor with many automatic features and an easy command-line interface to generate Metalink and Torrent files.
Metalink Generator can also be used to create Metalinks by filling out a Web form.
Metalink tools (GPL) Unix/Windows command line tools for generating Metalinks with hashes and mirror/p2p lists.
Dynamic online metalinks based on metadata. Automatically created metalinks based on metadata published by each mirror.
MirrorManager (MIT X11 license) is used by the Fedora Project
Fedora Project
The Fedora Project is an endeavor sponsored by Red Hat to co-ordinate the development of the Fedora operating system. Founded on September 2003 as a result of a merger between the Red Hat Linux and old Fedora Linux projects...

for dynamically listing mirrors.
The MirrorBrain (GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

, Apache License
Apache License
The Apache License is a copyfree free software license authored by the Apache Software Foundation . The Apache License requires preservation of the copyright notice and disclaimer....

) is a real-time Metalink generator and download redirector. It can either return Metalinks, or automatically redirect non-Metalink clients (per HTTP redirection) to a mirror server near them. Advanced features, as transparent negotiation of Metalinks, or embedding of PGP signatures, are fully supported. It is used by openSUSE
OpenSUSE
openSUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported openSUSE Project and sponsored by SUSE...

, OpenOffice.org
OpenOffice.org
OpenOffice.org, commonly known as OOo or OpenOffice, is an open-source application suite whose main components are for word processing, spreadsheets, presentations, graphics, and databases. OpenOffice is available for a number of different computer operating systems, is distributed as free software...

, and other projects.
Origo is a new and easy to use software development and hosting platform for open and closed source projects. Among many features, it has easy release management and mirroring with automatic metalink generation.

Example Metalink 4.0 .meta4 file

Metalink 4.0 files have the extension .meta4 and are XML

Extensible Markup Language

text files. They are served with the application/metalink4+xml Internet media type

Internet media type

An Internet media type, originally called a MIME type after MIME and sometimes a Content-type after the name of a header in several protocols whose value is such a type, is a two-part identifier for file formats on the Internet.The identifiers were originally defined in RFC 2046 for use in email...

.

2009-05-15T12:23:23Z

14471447
Example
1.0
en

A description of the example file for download.

3d6fece8033d146d8611eab4f032df738c8c1283620fd02a1f2bfec6e27d590d
ftp://ftp.example.com/example.ext
http://example.com/example.ext
http://example.com/example.ext.torrent

Example Metalink/HTTP header fields

Metalink in HTTP header fields makes use of existing standard HTTP header fields such as ETags

HTTP ETag

An ETag, or entity tag, is part of HTTP, the protocol for the World Wide Web. It is one of several mechanisms that HTTP provides for cache validation, and which allows a client to make conditional requests. This allows caches to be more efficient, and saves bandwidth, as a web server does not...

, Link header fields (for mirrors and P2P), and Instance Digests (for hashes).



Etag: "thvDyvhfIqlvFe+A9MYgxAfm1q5="

Link: ; rel=duplicate

Link: ; rel=duplicate

Link: ; rel=describedby; type="application/x-bittorrent"

Link: ; rel=describedby; type="application/metalink4+xml"

Link: ; rel=describedby; type="application/pgp-signature"

Digest: SHA-256=MWVkMWQxYTRiMzk5MDQ0MzI3NGU5NDEyZTk5OWY1ZGFmNzgyZTJlODYzYjRjYzFhOTlmNTQwYzI2M2QwM2U2MQ

Example Metalink 3.0 .metalink file
Metalink 3.0 files have the extension .metalink and are XML

Extensible Markup Language

text files.

example-md5-hash
example-sha1-hash

ftp://ftp.example.com/example.ext
ftp://ftp.example.net/example.ext
http://example.com/example.ext
http://example.net/example.ext
http://example.org/example.ext.torrent

External links

Metalink project official homepage
Making Metalinks article

Metalink standard

RFC 5854 - "The Metalink Download Description Format"
RFC 6249 - "Metalink/HTTP: Mirrors and Hashes"
Metalink 3.0 Specification

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.