These are ONE-way (to me) formats.

• OFX - OFX (Open Financial eXchange) is a standard for exchanging financial information for finance packages. It was created by Intuit, Checkfree and Microsoft in 1997.  Used by Money 98 onwards and sometimes called 'Active Statement'.  Used by Quicken and called QFX.  Contains information which can uniquely identify transactions to stop multiple transactions appearing in your file. Supports multiple accounts per file, so you would only need one download from each financial institution.
  
  OFX Home
  About OFX
  OFX Specification

  
  The QFX/Web Connect issue:
  
  Reportedly, Intuit charges financial institutions for QFX certification.
  The Quicken app maintains a database of FIs that offer Mac and/or Windows
  support (i.e. have paid Intuit for that platform),
  checks the Bank ID information in the QFX file against this database, and
  refuses to read the file if is not listed, even
  though the information in the file is perfectly valid.
  (QFX/OFX is an XML formatted text file, and is
  no different between the two platforms.)
  
   

• QFX – See OFX.

• OFC - OFC is an old Microsoft standard, used in Money versions from 97 up to 2004 (See also FAQ Article 31). It only supports one account per file.
   

• MD -  Files with a .md suffix are presumed to be in the MoneyDance binary format.
   

• MoneyDance XML - Files with a .xml suffix may be in the MoneyDance XML export format.  Essentially a readable alternative to the .md format.  Created by MoneyDance | File | Export.  Consumed by MoneyDance | File | Open.
   

• QIF -

  Intuit, the maker of Quicken, has dropped QIF imports in Quicken 2005 for the Windows® operating system and all future versions of its software.

  Developed more than 10 years ago, QIF was never intended for downloading data from financial institutions. (It was actually a technical support tool).  QIF users can mistakenly double post their transaction data, resulting in a bookkeeping nightmare.  Older versions (1998 & earlier) used 2-digit years.

  Data retrieved using OFX, however, prevents data from being posted twice by use of a unique system of built-in controls. Click here for more information about the sunset of QIF.

  (See FAQ Article 28).

• CSV – comma separated values