interfacing QuickBooks and ZenCart

Overview
ZenCart's target audience includes small businesses, many of whom also use QuickBooks and would like a way to exchange data between the two systems. Some considerable work has been done on this.

QODBC
Data in QuickBooks can be accessed via ODBC if you have the QODBC module (which is proprietary and not, unfortunately, available free of charge).

QBI QuickBooks Import
The other major avenue appears to be a ZenCart module for Quickbooks, called QBI QuickBooks Import. The module costs $50. It apparently generates .iif files, which QuickBooks knows how to import.
 * QBI Quickbooks Import official page
 * official support forum
 * QBI support forums at ZenCart:
 * main support thread
 * archived QuickBooks QBI forum: original statement of the problem
 * QuickBooks Endicia Zencart: discussion of ZenCart, QuickBooks, Endicia, and other shipping methods

Custom code
QuickBooks data can be exported in spreadsheet format, and the resulting text can be imported into ZenCart with a little custom coding.