Offline reader

An offline reader (sometimes called an offline navigator) is computer software that downloads e-mail, newsgroup posts or web pages, making them available when the computer is not connected to the Internet or, in the late 20th century, bulletin board systems. Offline readers are useful for portable computers and dial-up access.

Offline mail readers are computer programs that allow users to read electronic mail or other messages (for example, those on bulletin boards) with a minimum of connection time to the server storing the messages. This is accomplished by the server packaging up multiple messages into a compressed file for the user to download and then disconnect. The user then reads the message packet locally and any replies or new messages generated are packaged up and uploaded back to the server upon the next connection.

Most e-mail systems, like the common POP and IMAP formats used for internet mail, are on-line by their very nature. Most end user mailers, such as Outlook Express 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 systems 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 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-know examples include Silver Xpress's OPX, XRS, OMEM, SOUP and ZipMail.

Comparison

Name	Price
HTTrack	Free Software
BackStreet Browser	Freeware
WebCopier	Proprietary
Offline Explorer	Proprietary
Offline Browser	Proprietary

See also

• Online and offline