in reply to
how to access quickbooks from perl in linux
From a programming point of view, this is just accessing MySQL through Perl. A quite common and well-documented subject but rather than jump into the interface details, you should probably start by looking for a gentle introduction.
RSSBus SQLBroker is commercial. Check with the company for the details but the important part (for programming) is that their stuff can be accessed through MySQL, which you can access through Perl, etc.