The financial management software Quicken uses the extension QIF for files in its exchange format (Interchange Format). These files contain specially formatted ASCII (American Standard Code for Information Interchange) texts.
Although the format is designed by Intuit, it is open, so it is used by banks to provide data on account activity.
Quicken exists in several editions that do not all support this format. Other applications, such as Corel Quattro Pro, can import the data.
The online application Mint.Com can also handle these files.