xml2qif.pl - Takes a bunch of xml records, and converts them to bank account specific qif ledgers. Each new account_number.qif contains a summary of all transactions for that account number in the input xml files. Great for scraping historical records, althought I've found that kiwibank misses a transaction every now and then.
mergeSplits.pl file.qif mortgage.qif - Takes a kiwibank file.qif and incorporates the mortgage.qif The output is a modified source.qif file where the mortgage payments have correct interest, and principal splits. If you're importing the file into GNUcash you can automatically allocate interest to (increasing) costs, and principal to (decreasing) liabilities.