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

BitTorrent BitTorrent is a Protocol (computing), communication protocol for peer-to-peer file sharing (P2P), which enables users to distribute data and electronic files over the Internet in a Decentralised system, decentralized manner. The protocol is d ...

HTTP HTTP (Hypertext Transfer Protocol) 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, wher ...

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 dat ...

client written in C++ for

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

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 and

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, forming a peer-to-peer network of Node ...

(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 as IE or MSIE) is a deprecation, retired series of graphical user interface, graphical web browsers developed by Microsoft that were u ...

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 Gateway (telecommunications), gateways that implement network address translation (NAT). NAT traversal te ...

(''removed in v.1.03''), Peer Exchange (''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. 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 (networking), no ...

(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 curr ...

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

eMule eMule is a Free software, free peer-to-peer file sharing application for Microsoft Windows. Started in May 2002 as an alternative to eDonkey2000, eMule connects to both the eDonkey network and the Kad network. The distinguishing features of eM ...

program. When installed, it connects automatically to a server. The software includes an application to play Flash Video files ( .flv and .swf 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 ...

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 of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list; if people are on a blacklist, then they are considere ...

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 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 character encoding standard used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode Transformation Format 8-bit''. Almost every webpage is transmitted as UTF-8. UTF-8 supports all 1,112,0 ...

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