BitComet (originally named SimpleBT client from versions 0.11 to 0.37) is a cross-protocol BitTorrent,

HTTP 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 We ...

and

FTP The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...

client Client(s) or The Client may refer to: * Client (business) * Client (computing), hardware or software that accesses a remote service on another computer * Customer or client, a recipient of goods or services in return for monetary or other valuabl ...

written in

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

for Microsoft Windows and available in 52 different languages. Its first public release was version 0.28. The current BitComet logo has been used since version 0.50.

Features

The BitComet program is a multi-threaded multi-protocol hybrid

download manager A download manager is a software tool that manages the downloading of files from the Internet, which may be built: into a Web browser A web browser is application software for accessing websites. When a user requests a web page from a par ...

and BitTorrent

peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer ...

(P2P) file-sharing application. It supports simultaneous download tasks. To complete a particular download, it can draw parts of files from many sources across different P2P and client–server protocols. BitComet's main features include an embedded

Internet Explorer Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems ( ...

window to let users search for torrents. Along with the features typical of contemporary BitTorrent clients, it supports UPnP gateway configuration, bandwidth scheduling, Webseeding, selecting only certain files for download inside a torrent package,

NAT traversal Network address translation traversal is a computer networking technique of establishing and maintaining Internet protocol connections across gateways that implement network address translation (NAT). NAT traversal techniques are required for m ...

(''removed in v.1.03''),

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 ...

(''in older versions, using a proprietary protocol and starting with v.1.19 also by using the Extension Protocol, implementing a PEX mechanism compatible with μTorrent / Mainline PEX''), Initial-Seeding ( Super-Seeding) and support for

Magnet Links Magnet is a URI scheme that defines the format of magnet links, a de facto standard for identifying files ( URN) by their content, via cryptographic hash value rather than by their location. Although magnet links can be used in a number of con ...

. When downloading, BitComet provides the option to prioritize the first and last portions of media files so that files may be previewed before they are completely downloaded.
It also has a "Preview Download Mode" in which all pieces of the torrent will be, basically, downloaded sequentially thus allowing the user to play a media file while downloading (provided that the downloading speed and piece availability stay ahead of playing bitrate).
BitComet also allows users to share their .torrent files, on a searchable P2P network, with other BitComet users through the torrent sharing feature, named "Torrent Share" in previous versions and renamed to "Torrent Exchange" since v.1.17. BitComet uses the

Kademlia Kademlia is a distributed hash table for decentralized peer-to-peer computer networks designed by Petar Maymounkov and David Mazières in 2002. It specifies the structure of the network and the exchange of information through node lookups. Kademl ...

(mainline) DHT to operate even when the tracker is offline. BitComet is capable of downloading files over HTTP and FTP as well as bittorrent, and it includes download plugins for

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current ...

, Internet Explorer, and Maxthon. An optional plugin is available to connect to the eD2K network. The plugin is a modified version of the

GPL 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 to run, study, share, and modify the software. The license was the first copyleft for general u ...

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. The distinguishing features of eMule are ...

program. When installed, it connects automatically to a server. The software includes an application to play

Flash Video Flash Video is a container file format used to deliver digital video content (e.g., TV shows, movies, etc.) over the Internet using Adobe Flash Player version 6 and newer. Flash Video content may also be embedded within SWF files. There ar ...

files (

.flv Flash Video is a container file format used to deliver digital video content (e.g., TV shows, movies, etc.) over the Internet using Adobe Flash Player version 6 and newer. Flash Video content may also be embedded within SWF files. There are ...

and

.swf SWF ( ) is an Adobe Flash file format used for multimedia, vector graphics and ActionScript.Open Screen P ...

files). In February 2011, BitComet launched an anonymous downloading feature to its VIP customers. Using this feature, downloads will be handled by BitComet VIP servers and the real IP address of the user will be hidden.

Optional standalone software

BitComet.com offers a

BitTorrent tracker A BitTorrent tracker is a special type of server that assists in the communication between peers using the BitTorrent protocol. In peer-to-peer file sharing, a software client on an end-user PC requests a file, and portions of the requested fi ...

available for download from the official site. The FLV player program can also be downloaded separately and used independently of the BitComet software.

Search engine

The search site is google.atcomet.com

Controversy and criticism

Hash reporting

Since version 0.86 BitComet includes discussion and stat-tracking features which send information about torrents to the Bitcomet.com servers, including the torrent hash.

DHT exploit

During version 0.60, BitComet received bad publicity because its implementation of the DHT feature, which was new at the time, could be exploited to ignore the private flag of a tracker. This allowed users to avoid download and upload ratio restrictions, which are common on private trackers. Some private trackers responded to this by

blacklist Blacklisting is the action of a group or authority compiling a blacklist (or black list) of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list. If someone is on a blacklist, ...

ing version 0.60. BitComet developer RnySmile reverted the client back to version 0.59 in response to the blacklisting. The DHT exploit was fixed in version 0.61.

Padding files

Starting with version 0.85 (from early 2007), BitComet added a non-standard option to its torrent maker that ensures that no two data files in a multi-file torrent occupy the same BitTorrent "piece." To accomplish this, BitComet includes in the torrent a collection of empty "padding" files which houses the remainder of each file's last "piece". While these files are transparent to BitComet users, they damage the performance of other clients, because peers must devote resources and bandwidth to the padding files, with no benefit to the non-BitComet users. These files can constitute up to 10% of the total data transferred, creating a substantial drain on the swarm. BitComet developers added this feature to allow support of a feature called Long-Term Seeding in which the BitComet client can download files from other BitComet clients who have an identical file but not from the same torrent. It also allows the downloading of individual files from other non torrent sources like ED2K links. The addition of the padding file ensures that a complete version of the file can be obtained rather than being unable to complete the relevant file or last "piece" Creation of padding files has been enabled by default since version 0.85, and as of version 1.36 is still enabled by default.

FileHippo controversy

The download site

FileHippo FileHippo is a software downloading website that offers computer software for Windows. The website has sections listing most recently updated programs and most popular downloads, organised by category, with program information and link. Registrat ...

ceased carrying new versions of BitComet in April 2008, with this announcement.

As of April 2008 FileHippo will no longer be updating BitComet. As they have copied the FileHippo site text, files, images and update checker and are passing it off as original work. We recommend you use a different more reputable torrent client such as uTorrent.

This occurred after FileHippo reportedly noticed that the design and code of the AppHit.com site was very similar with the one FileHippo used, copying not only icons, but text from FileHippo's website and FileHippo's own original update checking software. Because AppHit and BitComet were contractual partners, FileHippo decided to stop carrying BitComet. BitComet has since terminated the partnership, by 2015 FileHippo made BitComet available once more.

Torrent file format

According to the official BitTorrent specification, 'All strings in a .torrent file that contains text must be

UTF-8 UTF-8 is a variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit''. UTF-8 is capable of ...

encoded'. When generating torrents on non-Latin character systems such as Chinese or Japanese, BitComet versions prior to 1.20 encoded the files' names and paths using the Windows Chinese/Japanese code page, and stored a UTF-8 version in a non-standard attribute. Starting with the March 2010 release of version 1.20, BitComet's torrent format now conforms to the standard.

References

External links

* {{BitTorrent BitTorrent clients C++ software Windows-only freeware 2003 software