Transmission is a

BitTorrent client The following is a general comparison of BitTorrent clients, which are computer programs designed for peer-to-peer file sharing using the BitTorrent protocol. The BitTorrent protocol coordinates segmented file transfer among peers connected i ...

which features a variety of user interfaces on top of a

cross-platform In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software r ...

back-end. Transmission is

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

licensed under the terms of the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the Four Freedoms (Free software), four freedoms to run, study, share, and modify the software. The license was th ...

, with parts under the

MIT License The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license comp ...

Features

Transmission allows users to quickly download files from multiple

peers Peers may refer to: People * Donald Peers * Edgar Allison Peers, English academician * Gavin Peers * John Peers, Australian tennis player * Kerry Peers * Mark Peers * Michael Peers * Steve Peers * Teddy Peers (1886–1935), Welsh international ...

on the Internet and to upload their own files. By adding

torrent file In the BitTorrent file distribution system, a torrent file or meta-info file is a computer file that contains metadata about files and folders to be distributed, and usually also a list of the network locations of trackers, which are computer ...

s via the user interface, users can create a queue of files to be downloaded and uploaded. Within the file selection menus, users can customise their downloads at the level of individual files. Transmission also

seeds A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm pl ...

, that is, it will automatically share downloaded content. Transmission allows the assigning of priorities to torrents and to files within torrents, thus potentially influencing which files download first. It supports the

Magnet URI scheme Magnet is a Uniform Resource Identifier, URI scheme that defines the format of magnet links, a de facto standard for identifying files (Uniform Resource Name, URN) by their content, via Cryptographic hash function, cryptographic hash value rathe ...

and encrypted connections. It allows torrent-file creation and

peer exchange Peer exchange or PEX is a communications protocol that augments the BitTorrent file sharing protocol. It allows a group of users (or peers) that are collaborating to share a given file to do so more swiftly and efficiently. In the original design ...

compatible with

Vuze Vuze (previously Azureus) is a BitTorrent client used to transfer files via the BitTorrent protocol. Vuze is written in Java, and uses the Azureus Engine. In addition to downloading data linked to .torrent files, Azureus allows users to view, p ...

and

μTorrent μTorrent, or uTorrent (see pronunciation) is a proprietary adware BitTorrent client owned and developed by Rainberry, Inc. with over 150 million users. It is the most widely used BitTorrent client outside China; globally only behind Xunlei. Th ...

. It includes a built-in web server so that users can control Transmission remotely via the web. It also supports automatic port-mapping using

UPnP Universal Plug and Play (UPnP) is a set of networking protocols that permits networked devices, such as personal computers, printers, Internet gateways, Wi-Fi access points and mobile devices to seamlessly discover each other's presence on the n ...

NAT-PMP NAT Port Mapping Protocol (NAT-PMP) is a network protocol for establishing network address translation (NAT) settings and port forwarding configurations automatically without user effort. The protocol automatically determines the external IPv4 a ...

, peer caching, blocklists for bad peers, bandwidth limits dependent on time-of-day, globally or per-torrent, and has partial support for IPv6. It allows the use of multiple trackers simultaneously,

Local Peer Discovery The Local Peer Discovery protocol, specified as BEP-14, is an extension to the BitTorrent file-distribution system. It is designed to support the discovery of local BitTorrent peers, aiming to minimize the traffic through the Internet service p ...

Micro Transport Protocol Micro Transport Protocol or μTP (sometimes also uTP) is an open UDP-based variant of the BitTorrent peer-to-peer file sharing protocol intended to mitigate poor latency and other congestion control problems found in conventional BitTorrent over ...

(μTP), and

UDP tracker The UDP tracker protocol is a high-performance low-overhead BitTorrent tracker protocol. It uses the stateless User Datagram Protocol (UDP) for data transmission instead of the HTTP protocol (over TCP) regular trackers use. The data is in a custom ...

. It does not support directly subscribing to

RSS RSS ( RDF Site Summary or Really Simple Syndication) is a web feed that allows users and applications to access updates to websites in a standardized, computer-readable format. Subscribing to RSS feeds can allow a user to keep track of many di ...

feeds containing torrent files for automatic download, but third-party add-ons can supply this functionality. macOS-specific features include

Dock A dock (from Dutch language, Dutch ''dok'') is the area of water between or next to one or a group of human-made structures that are involved in the handling of boats or ships (usually on or near a shore) or such structures themselves. The ex ...

and

Growl Growling is a low, guttural vocalization produced by predatory animals; producing ''growls''. Growling or growl may also refer to: Sounds * Death growl, the dominant singing style in death metal music * Stomach growl, or borborygmus, noise prod ...

notifications, automatic updates using

Sparkle Sparkle may refer to: * Sparkle (catamaran), a catamaran designed by Angus Primrose * Sparkle (drink), a lemon-flavored soft drink * Sparkle, a brand of paper towels owned by Georgia-Pacific * Dick Tracy#Plenty family, Sparkle Plenty, a character ...

and

Universal Binary The universal binary format is, in Apple parlance, a format for executable files that run natively on either PowerPC or Intel-manufactured IA-32 or Intel 64 or ARM64-based Macintosh computers. The format originated on NeXTStep as " Multi-Archi ...

(up until version 2.22).

Development

Transmission 1.60 and later removed support for

Mac OS X v10.4 Mac OS X Tiger (version 10.4) is the 5th major release of macOS, Apple's desktop and server operating system for Mac computers. Tiger was released to the public on April 29, 2005 for US$129.95 as the successor to Mac OS X 10.3 Panther. Som ...

. Currently, Transmission 1.54 is the last version that runs on Mac OS X 10.4. Although it is possible to compile later versions from source, either by downloading from the project's website or using a package manager like Fink or

MacPorts MacPorts, formerly DarwinPorts, is a package manager for macOS and Darwin. It is an open-source software project that aims to simplify the installation of other open source software. It's similar in function to Fink and the BSD ports collections ...

, it is unsupported and any bugs specific to 10.4 will not be fixed. Starting with Transmission 2.30 an Apple Mac with an

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

CPU is needed;

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

-based systems are no longer supported natively. The Transmission back-end (libTransmission) also serves as the basis of the Transmission

daemon Daimon or Daemon (Ancient Greek: , "god", "godlike", "power", "fate") originally referred to a lesser deity or guiding spirit such as the daimons of ancient Greek religion and mythology and of later Hellenistic religion and philosophy. The word ...

. The daemon supports a web front-end called Clutch. Older versions have been ported to form the basis of the update system for the video game ''

Metal Gear Online ''Metal Gear Online'' was a stealth third-person shooter video game for the PlayStation 3. It was an online multiplayer spin-off of the ''Metal Gear'' video game series. The starter pack of ''Online'' was available worldwide bundled with '' Metal ...

'' on

PlayStation 3 The PlayStation 3 (PS3) is a home video game console developed by Sony Interactive Entertainment, Sony Computer Entertainment. The successor to the PlayStation 2, it is part of the PlayStation brand of consoles. It was first released on Novemb ...

, as well as the backend for

ImageShack ImageShack is a subscription-based image hosting website headquartered at Los Gatos, California. Although ImageShack always had a subscription service, the majority of its revenue was originally produced from advertising related to its free ima ...

's BitTorrent service.

Distribution and ports

A portable version is available on

PortableApps.com PortableApps.com is a website offering free applications for Windows that have been specially packaged for portability. These portable applications are intended to be used from removable media such as USB flash drives. User data is stored in a s ...

Ports

Transmission is a set of lightweight BitTorrent clients (in GUI, CLI and daemon form). All its incarnations feature a very simple, intuitive interface on top on an efficient, cross-platform back-end. There are several transmission clients for different operating systems including

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 ...

macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

and

BeOS BeOS is an operating system for personal computers first developed by Be Inc. in 1990. It was first written to run on BeBox hardware. BeOS was positioned as a multimedia platform that could be used by a substantial population of desktop users a ...

ZETA Zeta (, ; uppercase Ζ, lowercase ζ; grc, ζῆτα, el, ζήτα, label= Demotic Greek, classical or ''zē̂ta''; ''zíta'') is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived f ...

. Each operating system front-end is built using native

widget toolkit A widget toolkit, widget library, GUI toolkit, or UX library is a library or a collection of libraries containing a set of graphical control elements (called ''widgets'') used to construct the graphical user interface (GUI) of programs. Most widg ...

s. For example, transmission-gtk uses the

GTK GTK (formerly GIMP ToolKit and GTK+) is a free and open-source cross-platform widget toolkit for creating graphical user interfaces (GUIs). It is licensed under the terms of the GNU Lesser General Public License, allowing both free and propriet ...

interface, transmission-qt the Qt interface, and transmission-cli a

command-line interface A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

. Transmission-remote-cli is an

ncurses ncurses (new curses) is a programming library providing an application programming interface (API) that allows the programmer to write text-based user interfaces (TUI) in a terminal-independent manner. It is a toolkit for developing "GUI-like" ...

interface for the transmission-daemon. Python-transmissionrpc is a Python module implementing the

JSON-RPC JSON-RPC is a remote procedure call protocol encoded in JSON. It is similar to the XML-RPC protocol, defining only a few data types and commands. JSON-RPC allows for notifications (data sent to the server that does not require a response) and for m ...

protocol for Transmission. An unofficial

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Ham ...

of Transmission using a

(CLI) on

iOS iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that powers many of the company's mobile devices, including the iPhone; the term also includes ...

was accomplished on 3 March 2008. In November 2010, iTransmission, another unofficial port, was released for jailbroken iPhones sporting a

GUI The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

that is capable of downloading directly to the device over WiFi or 3G. A Transmission remote was released for Android, with the name of ''Transdroid'' but does not currently support downloading directly to devices. On

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 ...

, Transmission-Qt can be built with

MinGW MinGW ("Minimalist GNU for Windows"), formerly mingw32, is a free and open source software development environment to create Microsoft Windows applications. MinGW includes a port of the GNU Compiler Collection (GCC), GNU Binutils for Windows ( ...

, the daemon and console tools can be built with

Cygwin Cygwin ( ) is a POSIX-compatible programming and runtime environment that runs natively on Microsoft Windows. Under Cygwin, source code designed for Unix-like operating systems may be compiled with minimal modification and executed. The Cygwin in ...

, also there are two third-party GUIs: transmission-remote-dotnet and Transmission Remote GUI, as well as unofficial full builds of Transmission's Qt Client., There is also an unofficial full build of Transmission

which can be run as a

Windows service In Windows NT operating systems, a Windows service is a computer program that operates in the background. It is similar in concept to a Unix daemon. A Windows service must conform to the interface rules and protocols of the Service Control Manager ...

. This same unofficial full build of Transmission

running as a

can be used for direct

streaming Streaming media is multimedia that is delivered and consumed in a continuous manner from a source, with little or no intermediate storage in network elements. ''Streaming'' refers to the delivery method of content, rather than the content it ...

of the downloading file(s). A port for all platforms enhanced with streaming of the downloading file(s) is located on

GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous ...

. It is also ported to the

Maemo Maemo is a software platform originally developed by Nokia, now developed by the community, for smartphones and Internet tablets. The platform comprises both the Maemo operating system and SDK. Maemo played a key role in Nokia's strategy to com ...

OS of the

Nokia N810 The Nokia N810 Internet tablet is an Internet appliance from Nokia, announced on 17 October 2007 at the Web 2.0 Summit in San Francisco. Despite Nokia's strong association with cellular products, the N810, like preceding tablets produced by Nok ...

internet tablet and

N900 The Nokia N900 is a smartphone made by Nokia. It supersedes the Nokia N810. Its default operating system, Maemo 5, is a Linux-based OS originally developed for the Nokia 770 Internet Tablet. It is the first Nokia device based upon the Texas I ...

smartphone as well as to the

MeeGo MeeGo is a discontinued Linux distribution hosted by the Linux Foundation, using source code from the operating systems Moblin (produced by Intel) and Maemo (produced by Nokia). Primarily targeted at mobile devices and information appliances in ...

Harmattan The Harmattan is a season in West Africa that occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara over West Africa into the ...

OS of the

Nokia Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational corporation, multinational telecommunications industry, telecommunications, technology company, information technology, and consumer electronics corporatio ...

N9 and N950 smartphones, on which it does download the torrents to the device.

Website breach

In March 2016,

Palo Alto Networks Palo Alto Networks, Inc. is an American multinational cybersecurity company with headquarters in Santa Clara, California. The core products is a platform that includes advanced firewalls and cloud-based offerings that extend those firewalls to ...

reported that Transmission's official website was compromised and tainted

.dmg DMG may refer to: Organizations Entertainment * Dames Making Games, a Canadian non-profit organization that encourages the participation of women, non-binary, femme and queer people in the creation of video games * Davidson Media Group, an Americ ...

files were uploaded to the site, using an

Apple Developer Apple Developer (formerly Apple Developer Connection) is Apple Inc.'s website for software development tools, application programming interfaces (APIs), and technical resources. It contains resources to help software developers write software for t ...

signature to bypass the OS X

gatekeeper A gatekeeper is a person who controls access to something, for example via a city gate or bouncer, or more abstractly, controls who is granted access to a category or status. Gatekeepers assess who is "in or out", in the classic words of managem ...

feature. The tainted packages installed a

ransomware Ransomware is a type of malware from cryptovirology that threatens to publish the victim's personal data or permanently block access to it unless a ransom is paid off. While some simple ransomware may lock the system without damaging any files, ...

application (a variant of

Linux.Encoder.1 Linux.Encoder (also known as ELF/Filecoder.A and Trojan.Linux.Ransom.A) is considered to be the first ransomware Trojan targeting computers running Linux. There are additional variants of this Trojan that target other Unix and Unix-like systems. Dis ...

, but recompiled for Mac, known as

KeRanger KeRanger (also known as OSX.KeRanger.A) is a ransomware trojan horse targeting computers running macOS. Discovered on March 4, 2016, by Palo Alto Networks, it affected more than 7,000 Mac users. KeRanger is remotely executed on the victim's compute ...

) that encrypts the user's files and attempts to force users to pay 1

Bitcoin Bitcoin ( abbreviation: BTC; sign: ₿) is a decentralized digital currency that can be transferred on the peer-to-peer bitcoin network. Bitcoin transactions are verified by network nodes through cryptography and recorded in a public distr ...

(worth roughly US$404 at the time of the attack) in order to get the decryption pack. The Transmission website advised Mac users to immediately upgrade to a new version that removes the malware-infected file. Apple revoked the developer certificate that was used to sign the tainted package, and added the package's signature to the XProtect anti-malware system.

Reception

Transmission is the default BitTorrent client of many

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

and

Linux distribution A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one ...

s, including

Ubuntu Ubuntu ( ) is a Linux distribution based on Debian and composed mostly of free and open-source software. Ubuntu is officially released in three editions: ''Desktop'', ''Server'', and ''Core'' for Internet of things devices and robots. All the ...

Mint MiNT is Now TOS (MiNT) is a free software alternative operating system kernel for the Atari ST system and its successors. It is a multi-tasking alternative to TOS and MagiC. Together with the free system components fVDI device drivers, XaAES g ...

Fedora A fedora () is a hat with a soft brim and indented crown.Kilgour, Ruth Edwards (1958). ''A Pageant of Hats Ancient and Modern''. R. M. McBride Company. It is typically creased lengthwise down the crown and "pinched" near the front on both sides ...

Puppy A puppy is a juvenile dog. Some puppies can weigh , while larger ones can weigh up to . All healthy puppies grow quickly after birth. A puppy's coat color may change as the puppy grows older, as is commonly seen in breeds such as the Yorksh ...

Zenwalk Zenwalk GNU/Linux is a desktop-focused Linux distribution founded by Jean-Philippe Guillemin. It is based on Slackware with very few modifications at system level making it 100% compatible with Slackware. Zenwalk aims to be a modern and multi- ...

, and the

GNOME A gnome is a mythological creature and diminutive spirit in Renaissance magic and alchemy, first introduced by Paracelsus in the 16th century and later adopted by more recent authors including those of modern fantasy literature. Its characte ...

flavor of

openSUSE openSUSE () is a free and open-source software, free and open source RPM Package Manager, RPM-based Linux distribution developed by the openSUSE project. The initial release of the community project was a beta version of SUSE Linux 10.0. Addi ...

. Fon ships its routers with Transmission pre-installed. ''

CNET ''CNET'' (short for "Computer Network") is an American media website that publishes reviews, news, articles, blogs, podcasts, and videos on technology and consumer electronics globally. ''CNET'' originally produced content for radio and televi ...

'' editor Paul Huges praised Transmission for its "simplicity, lightweight, as well as being feature-packed" and as of April 2017 the software ranked third in P2P downloads for Mac on ''CNET''.

Notes

References

External links

* {{DEFAULTSORT:Transmission (Bittorrent Client) 2005 software BeOS software BitTorrent clients for Linux Cross-platform software File sharing software that uses GTK File sharing software that uses Qt Free BitTorrent clients Free software programmed in C MacOS file sharing software Software that uses ncurses Software using the MIT license Unix Internet software