The Invisible Internet Project is an anonymous network layer that allows for censorship-resistant, peer to peer communication. Anonymous connections are achieved by encrypting the user's traffic, sending it through a volunteer-run network of 55,000 computers distributed around the world. Given the high number of possible paths the traffic can transit, a third party watching a full connection is unlikely; the software that implements this layer is called an "I2P router", a computer running I2P is called an "I2P node". I2P is free and open source, is published under multiple licenses. I2P is beta software since 2003; the software's developers emphasize that there are to be bugs in the beta version and that there has been insufficient peer review to date. However, they believe the code is now reasonably stable and well-developed, more exposure can help development of I2P; the network itself is message-based, but there is a library available to allow reliable streaming communication on top of it. All communication is end-to-end encrypted through garlic routing, the end points are cryptographic identifiers, so that neither sender nor recipient of a message need to reveal their IP address to the other side or to third-party observers.
Although many developers had been a part of the Invisible IRC Project and Freenet communities, there are significant differences between their designs and concepts. IIP was an anonymous centralized IRC server. Freenet is a censorship-resistant distributed data store. I2P is an anonymous peer-to-peer distributed communication layer designed to run any traditional internet service, as well as more traditional distributed applications. Many developers of I2P are known only under pseudonyms. While the previous main developer, jrandom, is on hiatus, such as zzz and Complication have continued to lead development efforts, are assisted by numerous contributors. I2P uses 2048bit ElGamal/AES256/SHA256+Session Tags encryption and Ed25519 EdDSA/ECDSA signatures. I2P has had a stable release every six to eight weeks. Updates are signed by the release manager. Since I2P is an anonymous network layer, it is designed so other software can use it for anonymous communication; as such, there are a variety of tools available for I2P or in development.
The I2P router is controlled through the router console, a web frontend accessed through a web browser. I2PTunnel is an application embedded into I2P that allows arbitrary TCP/IP applications to communicate over I2P by setting up "tunnels" which can be accessed by connecting to pre-determined ports on localhost. SAM is a protocol which allows a client application written in any programming language to communicate over I2P, by using a socket-based interface to the I2P router. BOB is a less complex app to router protocol similar to "SAM" Orchid Outproxy Tor plugin Any IRC client made for the Internet Relay Chat can work, once connected to the I2P IRC server. Several programs provide BitTorrent functionality for use within the I2P network. Users cannot connect to non-I2P torrents or peers from within I2P, nor can they connect to I2P torrents or peers from outside I2P. I2PSnark, included in the I2P install package, is a port of the BitTorrent client named Snark. Vuze known as Azureus, is a BitTorrent client that includes a plugin for I2P, allowing anonymous swarming through this network.
This plugin is still in an early stage of development, however it is fairly stable. I2P-BT is a BitTorrent client for I2P; this client is a modified version of the original BitTorrent 3.4.2 program which runs on MS Windows and most dialects of Unix in a GUI and command-line environment. It was developed by the individual known as'duck' on I2P in cooperation with'smeghead', it is no longer being developed. I2PRufus is an I2P port of the Rufus BitTorrent client. Robert is the most maintained I2PRufus fork. XD is a standalone BitTorrent client written in Go. Two Kad network clients exist for iMule and Nachtblitz. IMule is a port of eMule for I2P network. IMule has not been developed since 2013. IMule is made for anonymous file sharing. In contrast to other eDonkey clients, iMule only uses the Kademlia for proceeding to connect through I2P network, so no servers are needed. Nachtblitz is a custom client built on the. NET Framework; the latest version is 1.4.27, released on March 23, 2016. Nachtblitz includes.
I2Phex is a port of the popular Gnutella client Phex to I2P. It is stable and functional. A port of Tahoe-LAFS has been ported to I2P; this allows for files to be anonymously stored in Tahoe-LAFS grids. Vuze is the only torrent client that make clearnet torrents available on I2P and vice versa, by using a plugin that connects them to the I2P network. Depending on the client settings, torrents from the internet can be made available on I2P and torrents from I2P can be made available to the intern
WinMX is a freeware peer-to-peer file sharing program authored by Kevin Hearn and the team at Frontcode Technologies in 2000. According to one study, it was the number one source for online music in 2005 with an estimated 2.1 million users. Frontcode itself abandoned development of WinMX in September 2005, but developers brought the service back online within a few days by releasing patches. WinMX continues to be used by a community of enthusiasts. In 2009, Hearn released Tixati, an ad-free freeware p2p file sharing program based on the BitTorrent protocol, enhanced with a channels function where users can chat, share lists of web and media links and stream audio and video media with all communications being encrypted. More Hearn released Fopnu, a client and network with some similarities to WinMX. WinMX began its life as an OpenNAP client capable of connecting to several servers although Frontcode created a proprietary protocol, termed WinMX Peer Network Protocol, used starting with WinMX 2 in May 2001.
Frontcode had operated several cache servers to aid WPNP network operation. Downloads can be fast for popular songs since the user can run a "multi-point download" that downloads the same file in small pieces from several users; the WinMX program houses a few built-in features such as bandwidth monitoring, short messaging, hosting chatrooms and functions as an OpenNap client. Users could negotiate an exchange of their files with the help of the short messaging system or chat. After the transfers start, each has the option of selecting bandwidth for the other to make sure both transfers end more or less at the same time. There is an upper limit to the size of files; this design decision was to maintain Windows98 support. The program runs on Windows XP, Windows 7 and Windows 10 Operating systems as long as the relevant Microsoft C++ run time libraries are present. To get started, users connect as a primary or secondary user. A majority of the functions on the WPN are available to both users, but primary users need to spend more bandwidth, tend to have better connections, have the ability to host chat rooms.
Secondary users use little idle bandwidth, but their prolonged connection to the network is not always stable. WinMX users can share nearly every type of file using the network; the most common file types such as audio, video and archive files are available by default, all others could be configured in the program's settings. WinMX has a file-size restriction limiting shared files to 2GB in size. A user can only share 5,000 visible files for a Primary connection, 3,000 files for a Secondary connection; these limitations do not apply on OpenNap servers. Users can search for any file in WinMX; when a user sends out a search, the search is spread throughout the network. If a file is found, the hash of the file along with IP address and Primary node details of the user with the file is sent to the user who made the search. Searches can be made with hashes instead of words and numbers. WinMX allows a person to host chatrooms with its built-in Chat function. There are some rooms reserved for chat, some for trading files, some which allow both.
At its height WinMX had around 1,500 to 2,000 chatrooms at any given time in a multitude of languages. WinMX allows its users to message each other using its Private Message function regardless of whether or not they were in the same chat room or are downloading from/uploading to each other. However, settings allow any user to block messages from users, it is possible to host chatrooms in languages other than English, such as Japanese, German and Italian. WinMX started out as a Peer-to-Peer program, it can still connect to many OpenNap servers. These servers enable users to connect to a wider userbase and receive many more search results. Two advantages of running OpenNap is the ability to have a permanent list of friends called a hotlist and the ability to display an unlimited number of files for sharing. WinMX is natively English, but language files can be installed to translate menus into the following languages: Chinese, Finnish, German, Hungarian, Japanese, Polish, Russian, Sardinian and Swedish.
A fair number of the chat rooms are in Dutch or Italian. On September 13, 2005, Frontcode Technologies received a cease and desist letter from the RIAA demanding that they either implement filters to make it impossible for users to download copyrighted material from WinMX, or shut down. On September 21, 2005, the WinMX homepage went offline. By September 23, 2005, users were able to download two unofficial patches for WinMX from two unrelated websites; these patches worked by modifying the DNS lookup. When WinMX tries to find the Frontcode peer caches, it is instead directed to look up one of the new peer caches set up by the WinMX communities. Although these patches reconnected users, the official closure caused the user base to decrease, those who remained were split between the patches, causing rifts between them; each group wanted users to get reconnected using their patch and not the patch of the other group. In 2008 a new patch was released to coincide with the third anniversary of the two previous patches' release date.
Known as the "WinMX Community Patch", it was created through the joint effort of an independent, third-party programmer and the cooperative input and testing from the two communities. Sup
BitComet is a cross-protocol BitTorrent, HTTP and FTP client written in C++ 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. The BitComet program is a multi-threaded multi-protocol hybrid download manager and BitTorrent peer-to-peer 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 chief features include an embedded Internet Explorer window to let users search for torrents. Along with the features typical of contemporary BitTorrent clients, it supports UPnP gateway configuration, bandwidth scheduling, selecting only certain files for download inside a torrent package, NAT traversal, Peer Exchange, Initial-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 downloaded.
It has a "Preview Download Mode" in which all pieces of the torrent will be downloaded sequentially thus allowing the user to play a media file while downloading. BitComet 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 DHT to operate when the tracker is offline. BitComet is capable of downloading files over HTTP and FTP as well as bittorrent, it includes download plugins for Firefox, Internet Explorer, Maxthon. An optional plugin is available to connect to the eD2K network; the plugin is a modified version of the GPL eMule program. When installed, it connects automatically to a server; the software includes an application to play Flash Video files. In February 2011, BitComet launched 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.
BitComet.com offers a BitTorrent tracker available for download from the official site. The FLV player program can be downloaded separately and used independently of the BitComet software; the search site is google.atcomet.com 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. During version 0.60, BitComet received bad publicity because its implementation of the DHT feature, 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 blacklisting 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. Starting with version 0.85, 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 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, as of version 1.36 is still enabled by default.
In July 2007, Robb Topolski, a self-described “networking and protocol expert” conducted an independent analysis of most accusations leveled against BitComet including the DHT Exploit and Super-seeding controversies mentioned above. He found all but one of the claims to be unverifiable, he found that BitComet is not detrimental or malicious to the download or upload speeds of a BitTorrent swarm or the tracker. The one claim he verified as correct was that, "BitComet is a poor peer due to no upload slot control. Topolski's tests indicated that BitComet does lack upload slot control, but only when BitComet is seeding a torrent—that is, when BitComet is the only seeding peer in a swarm, it tends to seed less efficiently than the two other clients he tested. Topolski asserts that when BitComet is not the only seeding peer in the swarm, or when it is a non-seeding peer, upload slot control is managed exceptionally well; 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
File sharing is the practice of distributing or providing access to digital media, such as computer programs, documents or electronic books. File sharing may be achieved in a number of ways. Common methods of storage and dispersion include manual sharing utilizing removable media, centralized servers on computer networks, World Wide Web-based hyperlinked documents, the use of distributed peer-to-peer networking. Peer-to-peer file sharing is based on the peer-to-peer application architecture. Shared files on the computers of other users are indexed on directory servers. P2P technology was used by popular services like Limewire; the most popular protocol for P2P sharing is BitTorrent. Cloud-based file syncing and sharing services implement automated file transfers by updating files from a dedicated sharing directory on each user's networked devices. Files placed in this folder are accessible through a website and mobile app, can be shared with other users for viewing or collaboration; such services have become popular via consumer-oriented file hosting services such as Dropbox and Google Drive.
Rsync is a more traditional program released in 1996 which synchronizes files on a direct machine-to-machine basis. Data synchronization in general can use other approaches to share files, such as distributed filesystems, version control, or mirrors. Files were first exchanged on removable media. Computers were able to access remote files using filesystem mounting, bulletin board systems, FTP servers. Internet Relay Chat and Hotline enabled users to communicate remotely through chat and to exchange files; the mp3 encoding, standardized in 1991 and reduced the size of audio files, grew to widespread use in the late 1990s. In 1998, MP3.com and Audiogalaxy were established, the Digital Millennium Copyright Act was unanimously passed, the first mp3 player devices were launched. In June 1999, Napster was released as an unstructured centralized peer-to-peer system, requiring a central server for indexing and peer discovery, it is credited as being the first peer-to-peer file sharing system. Gnutella, eDonkey2000, Freenet were released in 2000, as MP3.com and Napster were facing litigation.
Gnutella, released in March, was the first decentralized file sharing network. In the gnutella network, all connecting software was considered equal, therefore the network had no central point of failure. In July, Freenet became the first anonymity network. In September the eDonkey2000 client and server software was released. In 2001, Kazaa and Poisoned for the Mac was released, its FastTrack network was distributed, though unlike gnutella, it assigned more traffic to'supernodes' to increase routing efficiency. The network was proprietary and encrypted, the Kazaa team made substantial efforts to keep other clients such as Morpheus off of the FastTrack network. In July 2001, Napster was sued by several recording companies and lost in A&M Records, Inc. v. Napster, Inc.. In the case of Napster, it has been ruled that an online service provider could not use the "transitory network transmission" safe harbor in the DMCA if they had control of the network with a server. Shortly after its loss in court, Napster was shut down to comply with a court order.
This drove users to other P2P applications and file sharing continued its growth. The Audiogalaxy Satellite client grew in popularity, the LimeWire client and BitTorrent protocol were released; until its decline in 2004, Kazaa was the most popular file sharing program despite bundled malware and legal battles in the Netherlands and the United States. In 2002, a Tokyo district court ruling shut down File Rogue, the Recording Industry Association of America filed a lawsuit that shut down Audiogalaxy. From 2002 through 2003, a number of BitTorrent services were established, including Suprnova.org, isoHunt, TorrentSpy, The Pirate Bay. In 2002, the RIAA was filing lawsuits against Kazaa users; as a result of such lawsuits, many universities added file sharing regulations in their school administrative codes. With the shutdown of eDonkey in 2005, eMule became the dominant client of the eDonkey network. In 2006, police raids took down the Razorback2 eDonkey server and temporarily took down The Pirate Bay.“The File Sharing Act was launched by Chairman Towns in 2009, this act prohibited the use of applications that allowed individuals to share federal information amongst one another.
On the other hand, only specific file sharing application were made available to federal computers”. In 2009, the Pirate Bay trial ended in a guilty verdict for the primary founders of the tracker; the decision was appealed, leading to a second guilty verdict in November 2010. In October 2010, Limewire was forced to shut down following a court order in Arista Records LLC v. Lime Group LLC but the gnutella network remains active through open source clients like Frostwire and gtk-gnutella. Furthermore, multi-protocol file sharing software such as MLDonkey and Shareaza adapted in order to support all the major file sharing protocols, so users no longer had to install and configure multiple file sharing programs. On January 19, 2012, the United States Department of Justice shut down the popular domain of Megaupload; the file sharing site has claimed to have over 50,000,000 people a day. Kim Dotcom was arrested with three associates in New Zealand on January 20, 2012 and is awaiting extradition; the case involving the downfall of the world's largest and most popular file sharing site was not well received, with hac
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri
Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are privileged, equipotent participants in the application, they are said to form a peer-to-peer network of nodes. Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client-server model in which the consumption and supply of resources is divided. Emerging collaborative P2P systems are going beyond the era of peers doing similar things while sharing resources, are looking for diverse peers that can bring in unique resources and capabilities to a virtual community thereby empowering it to engage in greater tasks beyond those that can be accomplished by individual peers, yet that are beneficial to all the peers.
While P2P systems had been used in many application domains, the architecture was popularized by the file sharing system Napster released in 1999. The concept has inspired new philosophies in many areas of human interaction. In such social contexts, peer-to-peer as a meme refers to the egalitarian social networking that has emerged throughout society, enabled by Internet technologies in general. While P2P systems had been used in many application domains, the concept was popularized by file sharing systems such as the music-sharing application Napster; the peer-to-peer movement allowed millions of Internet users to connect "directly, forming groups and collaborating to become user-created search engines, virtual supercomputers, filesystems." The basic concept of peer-to-peer computing was envisioned in earlier software systems and networking discussions, reaching back to principles stated in the first Request for Comments, RFC 1. Tim Berners-Lee's vision for the World Wide Web was close to a P2P network in that it assumed each user of the web would be an active editor and contributor and linking content to form an interlinked "web" of links.
The early Internet was more open than present day, where two machines connected to the Internet could send packets to each other without firewalls and other security measures. This contrasts to the broadcasting-like structure of the web; as a precursor to the Internet, ARPANET was a successful client-server network where "every participating node could request and serve content." However, ARPANET was not self-organized, it lacked the ability to "provide any means for context or content-based routing beyond'simple' address-based routing."Therefore, USENET, a distributed messaging system, described as an early peer-to-peer architecture, was established. It was developed in 1979 as a system; the basic model is a client-server model from the user or client perspective that offers a self-organizing approach to newsgroup servers. However, news servers communicate with one another as peers to propagate Usenet news articles over the entire group of network servers; the same consideration applies to SMTP email in the sense that the core email-relaying network of mail transfer agents has a peer-to-peer character, while the periphery of e-mail clients and their direct connections is a client-server relationship.
In May 1999, with millions more people on the Internet, Shawn Fanning introduced the music and file-sharing application called Napster. Napster was the beginning of peer-to-peer networks, as we know them today, where "participating users establish a virtual network independent from the physical network, without having to obey any administrative authorities or restrictions." A peer-to-peer network is designed around the notion of equal peer nodes functioning as both "clients" and "servers" to the other nodes on the network. This model of network arrangement differs from the client–server model where communication is to and from a central server. A typical example of a file transfer that uses the client-server model is the File Transfer Protocol service in which the client and server programs are distinct: the clients initiate the transfer, the servers satisfy these requests. Peer-to-peer networks implement some form of virtual overlay network on top of the physical network topology, where the nodes in the overlay form a subset of the nodes in the physical network.
Data is still exchanged directly over the underlying TCP/IP network, but at the application layer peers are able to communicate with each other directly, via the logical overlay links. Overlays are used for indexing and peer discovery, make the P2P system independent from the physical network topology. Based on how the nodes are linked to each other within the overlay network, how resources are indexed and located, we can classify networks as unstructured or structured. Unstructured peer-to-peer networks do not impose a particular structure on the overlay network by design, but rather are formed by nodes that randomly form connections to each other.. Because there is no structure globally imposed upon them, unstructured networks are easy to build and allow for localized optimizations to different regions of the overlay; because the role of all peers in the network is the same, unstructured networks are robust in the face of high rates of "churn"—that is, when large numbers of peers are joining and leaving the network.