Quicken Interchange Format (QIF) is an open specification for reading and writing financial data to media (http://en.wikipedia.org/wiki/Quicken_Interchange_Format )
parseQif in tcl (http://homepage.mac.com/levanj/TclTk/ ).
PDQ Ledger is a Financial application that has been written entirely in Tcl/Tk (http://pdqi.com/ledger.html ). There is also support for importing QIF transaction files (LedgerQIF).