An offline reader (sometimes called an offline browser or offline navigator) is

computer software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

that downloads

e-mail Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" meant ...

newsgroup A Usenet newsgroup is a repository usually within the Usenet system, for messages posted from users in different locations using the Internet. They are discussion groups and are not devoted to publishing news. Newsgroups are technically distinct ...

posts or web pages, making them available when the computer is

offline In computer technology and telecommunications, online indicates a state of connectivity and offline indicates a disconnected state. In modern terminology, this usually refers to an Internet connection, but (especially when expressed "on line" or ...

: not connected to a server. Offline readers are useful for

portable computer A portable computer is a computer designed to be easily moved from one place to another and included a display and keyboard together, with a single plug, much like later desktop computers called '' all-in-ones'' (AIO), that integrate the sy ...

s and

dial-up access Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telepho ...

Variations

Website-mirroring software

Website mirroring software is software that allows for the download of a copy of an entire

website A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google Search, Google, Facebook, Amaz ...

to the local hard disk for

offline browsing An offline reader (sometimes called an offline browser or offline navigator) is computer software that downloads e-mail, newsgroup posts or web pages, making them available when the computer is offline: not connected to a server. Offline readers ...

. In effect, the downloaded copy serves as a

mirror A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...

of the original site.

Web crawler A Web crawler, sometimes called a spider or spiderbot and often shortened to crawler, is an Internet bot that systematically browses the World Wide Web and that is typically operated by search engines for the purpose of Web indexing (''web spid ...

software such as

Wget GNU Wget (or just Wget, formerly Geturl, also written as its package name, wget) is a computer program that retrieves content from web servers. It is part of the GNU Project. Its name derives from "World Wide Web" and " ''get''." It supports dow ...

can be used to generate a site mirror.

Offline mail and news readers

Offline mail readers are

computer program A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer program ...

s that allow users to read

electronic mail Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronics, electronic (digital media, digital) version of, or counterpart to, mail, ...

or other messages (for example, those on

bulletin board systems A bulletin board system (BBS), also called computer bulletin board service (CBBS), is a computer server running software that allows users to connect to the system using a terminal program. Once logged in, the user can perform functions such as ...

) with a minimum of connection time to the server storing the messages. BBS

server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

s accomplished this by packaging up multiple messages into a compressed file, e.g., a QWK packet, for the user to download using, e.g., Xmodem,

Ymodem YMODEM is a file transfer protocol used between microcomputers connected together using modems. It was primarily used to transfer files to and from bulletin board systems. YMODEM was developed by Chuck Forsberg as an expansion of XMODEM and was f ...

Zmodem ZMODEM is an inline file transfer protocol developed by Chuck Forsberg in 1986, in a project funded by Telenet in order to improve file transfers on their X.25 network. In addition to dramatically improved performance compared to older protocols, ...

, and then disconnect. The user reads and replies to the messages locally and packages up and uploads any replies or new messages back to the server upon the next connection. Internet mail servers using

POP3 In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. POP version 3 (POP3) is the version in common use, and along with IMAP the most common p ...

IMAP4 In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by . IMAP was designed with the goal of per ...

send the messages uncompressed as part of the protocol, and outbound messages using

SMTP The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typical ...

are also uncompressed. Offline news readers using

NNTP The Network News Transfer Protocol (NNTP) is an application protocol used for transporting Usenet news articles (''netnews'') between news servers, and for reading/posting articles by the end user client applications. Brian Kantor of the Univers ...

are similar, but the messages are organized into news groups. Most e-mail protocols, like the common POP3 and

IMAP In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by . IMAP was designed with the goal of per ...

4 used for

internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...

mail, need be on-line only during message transfer; the same applies to the

protocol used by

Usenet Usenet () is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Ellis conceived the idea in 1979, and it was ...

(Network news). Most end-user mailers, such as

Outlook Express Outlook Express, formerly known as Microsoft Internet Mail and News, is a discontinued email and news client included with Internet Explorer versions 3.0 through to 6.0. As such, it was bundled with several versions of Microsoft Windows, from ...

and

AOL AOL (stylized as Aol., formerly a company known as AOL Inc. and originally known as America Online) is an American web portal and online service provider based in New York City. It is a brand marketed by the current incarnation of Yahoo (2017� ...

, can be used offline even if they are mainly intended to be used online, but some mailers such as

Juno Juno commonly refers to: *Juno (mythology), the Roman goddess of marriage and queen of the gods *Juno (film), ''Juno'' (film), 2007 Juno may also refer to: Arts, entertainment and media Fictional characters *Juno, in the film ''Jenny, Juno'' *Ju ...

are mainly intended to be used offline. Off-line mail readers are generally considered to be those systems that did not originally offer such functionality, notably on

bulletin board system A bulletin board system (BBS), also called computer bulletin board service (CBBS), is a computer server running software that allows users to connect to the system using a terminal program. Once logged in, the user can perform functions such as ...

s where toll charges and tying up telephone lines were a major concern. Users of large networks such as FidoNet regularly used offline mail readers, and it was also used for

UseNet Usenet () is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Ellis conceived the idea in 1979, and it was ...

messages on the internet, which is also an online system. The two most common formats for FidoNet BBS's were Blue Wave and QWK. Less well-known examples include Silver Xpress's OPX, XRS, OMEM,

SOUP Soup is a primarily liquid food, generally served warm or hot (but may be cool or cold), that is made by combining ingredients of meat or vegetables with stock, milk, or water. Hot soups are additionally characterized by boiling solid ing ...

Variations

Website-mirroring software

Offline mail and news readers

List

See also

Notes

References