The Quicken Interchange Format (QIF) is a file format developed by Intuit for exporting and importing financial data between different applications. It is primarily used to transfer data to and from Quicken, a popular personal finance management software. QIF files store information about bank accounts, credit card transactions, investment accounts, and other financial data. The format is a plain text format, making it relatively easy to parse and manipulate. However, it has limitations compared to newer formats like OFX (Open Financial Exchange), particularly in handling complex investment transactions and security. QIF files are often used for importing historical financial data into Quicken or other financial software, or for exporting data from older versions of Quicken. While still supported by some applications, its use is declining in favor of more modern and robust formats.