QIF, in the context of computer applications, stands for Quicken Interchange Format. QIF is an open specification for reading and writing financial data to media (i.e. files). A QIF file typically has the following structure:

!Type:type identifier string
[single character line code]Literal String Data
...
^
[single character line code]Literal String Data
...
^

Each record is ended by the ^ (caret). All the data in the file is stored in ASCII strings, and the file could be edited in any text editor (such as Notepad in Microsoft Windows).

QIF is older than Open Financial Exchange (OFX). The inability to reconcile imported transactions against the current account information is one of the primary short comings of QIF. It is commonly supported by financial institutions to supply downloadable information to account holders. Most personal money management software (Microsoft Money, Intuit Quicken) can read QIF files to import information. Banks that support integrated online banking (i.e. as part of Money or Quicken) usually use OFX instead of QIF.

The full specification is available here: http://www.respmech.com/mym2qifw/qif_new.htm