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

computer software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

that downloads

e-mail Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the ...

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 not only discussion groups or conversations, but also a repository to publish articles, start ...

posts or

web page A web page (or webpage) is a World Wide Web, Web document that is accessed in a web browser. A website typically consists of many web pages hyperlink, linked together under a common domain name. The term "web page" is therefore a metaphor of pap ...

s, 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 as "on li ...

: 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, as opposed to those designed to remain stationary at a single location such as desktops and workstations. These computers usually include a display a ...

s and dial-up access.

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 any web page whose content is identified by a common domain name and is published on at least one web server. Websites are typically dedicated to a particular topic or purpose, such as news, educatio ...

to the local hard disk for offline browsing. In effect, the downloaded copy serves as a

mirror A mirror, also known as a looking glass, is an object that Reflection (physics), reflects an image. Light that bounces off a mirror forms an image of whatever is in front of it, which is then focused through the lens of the eye or a camera ...

of the original site.

Web crawler 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 spider ...

software such as Wget 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 Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

s that allow users to read

electronic mail Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the ...

or other messages (for example, those on

bulletin board systems A bulletin board system (BBS), also called a 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 performs functions such as ...

) with a minimum of connection time to the server storing the messages. BBS servers 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 XMODEM is a simple file transfer protocol developed as a quick hack by Ward Christensen for use in his 1977 MODEM.ASM terminal program. It allowed users to transmit files between their computers when both sides used MODEM. Keith Petersen made a ...

, Ymodem, Zmodem, 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. Today, POP version 3 (POP3) is the most commonly used version. Together with IMAP, i ...

or IMAP4 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 typi ...

are also uncompressed. Offline news readers using NNTP 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 network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

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

Usenet Usenet (), a portmanteau of User's Network, is a worldwide distributed discussion system available on computers. It was developed from the general-purpose UUCP, Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Elli ...

(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 to 6.0. As such, it was bundled with several versions of Microsoft Windows, from Windows ...

and AOL, can be used offline even if they are mainly intended to be used online, but some mailers such as Juno 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 a computer bulletin board service (CBBS), is a computer server running list of BBS software, software that allows users to connect to the system using a terminal program. Once logged in, the user perfor ...

s where toll charges and tying up telephone lines were a major concern. Users of large networks such as

FidoNet __ / \ /, oo \ (_, /_) _`@/_ \ _ , , \ \\ , (*) , \ )) ______ , __U__, / \// / FI ...

regularly used offline mail readers, and it was also used for

UseNet Usenet (), a portmanteau of User's Network, is a worldwide distributed discussion system available on computers. It was developed from the general-purpose UUCP, Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Elli ...

messages on the internet, which is also an on-line 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, OMEN,

SOUP Soup is a primarily liquid food, generally served warm or hot – though it is sometimes served chilled – made by cooking or otherwise combining meat or vegetables with Stock (food), stock, milk, or water. According to ''The Oxford Compan ...

Variations

Website-mirroring software

Offline mail and news readers

List

See also

Notes

References

External links